阅读说明：本技术 一种车辆的制动方法 (Vehicle braking method ) 是由 不公告发明人 于 2017-07-01 设计创作，主要内容包括：本发明涉及一种车辆的制动方法,其下坡自动排气制动装置包括手动换向阀、换挡气缸、换挡操作阀、蝶阀气缸、排气蝶阀、气包、第一气控阀、电磁换向阀、第二气控阀、水管组件、液位开关和电源,电磁换向阀的执行口A口分别与第一气控阀的气控口K口、第二气控阀的气控口K口和蝶阀气缸的无杆腔连通,液位开关串接在电磁换向阀与电源之间,第一气控阀的执行口A口与手动换向阀的进气口P口连通,手动换向阀的执行口A口和执行口B口分别与换挡气缸的无杆腔和有杆腔连通,换挡气缸的第一活塞杆与换挡操作阀的阀杆固定连接；第二气控阀的执行口A口与换挡气缸的无杆腔连通。车辆下大坡时可自动排气制动且车辆排气制动时可自动挂高速挡。(The invention relates to a braking method of a vehicle, wherein a downhill automatic exhaust braking device comprises a manual reversing valve, a gear shifting cylinder, a gear shifting operation valve, a butterfly valve cylinder, an exhaust butterfly valve, an air bag, a first pneumatic control valve, an electromagnetic reversing valve, a second pneumatic control valve, a water pipe assembly, a liquid level switch and a power supply, wherein an execution port A of the electromagnetic reversing valve is respectively communicated with a pneumatic control port K of the first pneumatic control valve, a pneumatic control port K of the second pneumatic control valve and a rodless cavity of the butterfly valve cylinder; and an execution port A of the second pneumatic control valve is communicated with a rodless cavity of the gear shifting cylinder. When the vehicle descends a heavy slope, the exhaust brake can be automatically carried out, and when the exhaust brake of the vehicle is carried out, the high-speed gear can be automatically engaged.)

1. The utility model provides a downhill path automatic exhaust brake's of vehicle working method, above-mentioned downhill path automatic exhaust brake includes manual switching-over valve (1), shift cylinder (2), shift operating valve (3), butterfly valve cylinder (7), exhaust butterfly valve (8) and gas bag (9), its characterized in that: the device also comprises a first pneumatic control valve (4), an electromagnetic directional valve (5), a second pneumatic control valve (6), a water pipe assembly (10), a liquid level switch (11) and a power supply (12); the water pipe assembly (10) comprises a transverse pipe (10-1) and a longitudinal pipe (10-2), the longitudinal pipe (10-2) is located at one end of the transverse pipe (10-1), the longitudinal pipe (10-2) is fixedly connected to the top wall of the transverse pipe (10-1), and the inner cavity of the transverse pipe (10-1) is communicated with the inner cavity of the longitudinal pipe (10-2); an air inlet P port of the electromagnetic directional valve (5) is communicated with the air bag (9), an execution port A port of the electromagnetic directional valve (5) is respectively communicated with an air control port K port of the first air control valve (4), an air control port K port of the second air control valve (6) and a rodless cavity of the butterfly valve cylinder (7), an air outlet T port of the electromagnetic directional valve (5) is communicated with the atmosphere, and a terminal K of the electromagnetic directional valve (5) is electrically connected with the power supply (12); the liquid level switch (11) is arranged on a longitudinal pipe (10-2) of the water pipe assembly (10) and is connected in series in a connecting circuit between the electromagnetic directional valve (5) and the power supply (12), and a detection element of the liquid level switch (11) is inserted into the longitudinal pipe (10-2);

when the water level at the liquid level switch (11) is higher than a set value, the liquid level switch (11) is switched on, and a terminal K of the electromagnetic directional valve (5) is electrified; a second cylinder body (7-2) of the butterfly valve cylinder (7) is hinged to a frame of the vehicle, and a second piston rod (7-1) of the butterfly valve cylinder (7) is fixedly connected with a handle (8-1) of the exhaust butterfly valve (8); an air inlet port P of the first pneumatic control valve (4) is communicated with the air bag (9), and an execution port A of the first pneumatic control valve (4) is communicated with an air inlet port P of the manual reversing valve (1); an execution port A and an execution port B of the manual reversing valve (1) are respectively communicated with a rodless cavity and a rod cavity of the gear shifting cylinder (2), and a gas outlet T of the manual reversing valve (1) is communicated with the atmosphere; the first cylinder body (2-2) of the gear shifting cylinder (2) is hinged to a frame of a vehicle, a first piston rod (2-1) of the gear shifting cylinder (2) is fixedly connected with a valve rod (3-1) of a gear shifting operation valve (3), an air inlet port P of the second pneumatic control valve (6) is communicated with an air bag (9), and an execution port A of the second pneumatic control valve (6) is communicated with a rodless cavity of the gear shifting cylinder (2);

the working method comprises the following steps: when the water level at the liquid level switch is higher than a set value, the liquid level switch is switched on; therefore, when the vehicle runs on a heavy slope or downhill, the water level at the longitudinal pipe rises, when the water level at the liquid level switch in the longitudinal pipe rises to a set value, the liquid level switch is switched on, the terminal K of the electromagnetic directional valve is electrified, the port P of the air inlet of the electromagnetic directional valve is communicated with the port A of the execution port, the pressure gas in the air bag reaches the rodless cavity of the butterfly valve cylinder through the electromagnetic directional valve, the second piston rod of the butterfly valve cylinder drives the handle of the exhaust butterfly valve to rotate, so that the exhaust butterfly valve is in a closed state, namely, exhaust braking is automatically performed when the vehicle runs on the heavy slope.

2. The method of operation of claim 1, wherein: when the vehicle is subjected to exhaust braking, the pressure gas in the gas bag simultaneously reaches a gas control port K of the first gas control valve and a gas control port K of the second gas control valve through the electromagnetic directional valve, so that a gas inlet P port of the first gas control valve is not communicated with an execution port A, and a gas inlet P port of the second gas control valve is communicated with the execution port A, so that the pressure gas in the gas bag cannot reach the manual directional valve through the first gas control valve and then reach the gear shifting cylinder, but the pressure gas in the gas bag can reach a rodless cavity of the gear shifting cylinder through the second gas control valve, and the vehicle can be automatically hung on a high-speed gear 3 during exhaust braking.

3. The method of operation of claim 1, wherein: the downhill automatic exhaust brake device also comprises a third pneumatic control valve (13) and a flameout cylinder (14); an air inlet P port of the third pneumatic control valve (13) is communicated with the air bag (9), an execution port A port of the third pneumatic control valve (13) is communicated with a rod cavity of the flameout air cylinder (14), and a control port K port of the third pneumatic control valve (13) is communicated with an execution port A port of the electromagnetic directional valve (5); a third piston rod (14-1) of the flameout cylinder (14) is fixedly connected with a flameout switch of the diesel engine, and a third cylinder body (14-2) of the flameout cylinder (14) is hinged to a frame of the vehicle;

a terminal K of the electromagnetic directional valve (5) is electrified, when an air inlet P port of the electromagnetic directional valve (5) is communicated with an execution port A port, pressure gas in the gas bag (9) can reach a control port K port of a third pneumatic control valve (13) through the electromagnetic directional valve (5), the air inlet P port of the third pneumatic control valve (13) is communicated with the execution port A port, the pressure gas enters a rod cavity of the flameout cylinder (14), and a piston rod (14-1) of the flameout cylinder (14) drives a flameout switch of the diesel engine to act, so that the diesel engine is flameout.

Technical Field

The present invention relates to a braking method for a vehicle.

Background

When the vehicle runs on a heavy slope or a downhill, the vehicle needs to be braked frequently, so that the temperature of the brake is increased, the braking efficiency is reduced, and the abrasion consumption of the brake is increased. The exhaust brake function is necessary supplement to the existing vehicles, the exhaust brake is generally started by a manual switch, and when the vehicle runs on a heavy slope or a downhill, a transmission selects a high-speed gear, so that the fault that the engine is damaged due to overhigh rotating speed of the engine during the exhaust brake can be prevented. When the exhaust brake is used, the neutral position can not be engaged, otherwise, the exhaust brake is invalid, and a driving accident can also occur. In addition, the vehicle is generally turned off when exhaust braking is performed. Chinese patent document CN106089453A (application No. 201610611056X) discloses an exhaust brake extinction system for a vehicle, which can realize that the vehicle cannot perform exhaust brake when in neutral gear to improve the safety performance of the vehicle, and can also realize that the vehicle can automatically extinguish when in exhaust brake, but the exhaust brake of the exhaust brake extinction system for the vehicle still needs to be performed by manually operating an exhaust butterfly valve switch, i.e. the exhaust brake cannot be performed automatically, and the exhaust brake extinction system for the vehicle can only realize that the exhaust brake cannot be performed when in neutral gear, and at this time, the vehicle still needs to be firstly put into a high-speed gear, and then the exhaust brake can be performed by manually operating the exhaust butterfly valve switch, so the operation is very troublesome.

Disclosure of Invention

The invention aims to provide a working method of a vehicle, which can automatically perform exhaust braking when the vehicle descends a heavy slope and can automatically engage a high-speed gear when the vehicle performs exhaust braking.

In order to achieve the purpose, the technical scheme of the invention is as follows: a working method of a vehicle comprises a downhill automatic exhaust braking device, wherein the downhill automatic exhaust braking device comprises a manual reversing valve, a gear shifting cylinder, a gear shifting operation valve, a butterfly valve cylinder, an exhaust butterfly valve and an air bag, and further comprises a first pneumatic control valve, an electromagnetic reversing valve, a second pneumatic control valve, a water pipe assembly, a liquid level switch and a power supply; the water pipe assembly comprises a transverse pipe and a longitudinal pipe, the longitudinal pipe is positioned at one end of the transverse pipe and fixedly connected to the top wall of the transverse pipe, and the inner cavity of the transverse pipe is communicated with the inner cavity of the longitudinal pipe; an air inlet P port of the electromagnetic directional valve is communicated with the air bag, an execution port A port of the electromagnetic directional valve is respectively communicated with an air control port K port of the first air control valve, an air control port K port of the second air control valve and a rodless cavity of the butterfly valve cylinder, an air outlet T port of the electromagnetic directional valve is communicated with the atmosphere, and a wiring terminal K of the electromagnetic directional valve is electrically connected with a power supply; the liquid level switch is arranged on a longitudinal pipe of the water pipe assembly and is connected in series in a connecting circuit between the electromagnetic directional valve and the power supply, and a detection element of the liquid level switch is inserted into the longitudinal pipe; when the water level at the liquid level switch is higher than a set value, the liquid level switch is switched on, and a terminal K of the electromagnetic directional valve is electrified; the second cylinder body of the butterfly valve cylinder is hinged to a frame of the vehicle, and a second piston rod of the butterfly valve cylinder is fixedly connected with a handle of the exhaust butterfly valve; an air inlet port P of the first pneumatic control valve is communicated with the air bag, and an execution port A of the first pneumatic control valve is communicated with an air inlet port P of the manual reversing valve; an execution port A and an execution port B of the manual reversing valve are respectively communicated with a rodless cavity and a rod cavity of the gear shifting cylinder, and a gas outlet T of the manual reversing valve is communicated with the atmosphere; the first cylinder body of the gear shifting cylinder is hinged to a frame of a vehicle, a first piston rod of the gear shifting cylinder is fixedly connected with a valve rod of a gear shifting operation valve, an air inlet P port of the second pneumatic control valve is communicated with an air bag, and an execution port A port of the second pneumatic control valve is communicated with a rodless cavity of the gear shifting cylinder.

The device also comprises a third pneumatic control valve and a flameout cylinder; the port P of the air inlet of the third pneumatic control valve is communicated with the air bag, the port A of the execution port of the third pneumatic control valve is communicated with the rod cavity of the flameout cylinder, and the port K of the control port of the third pneumatic control valve is communicated with the port A of the execution port of the electromagnetic directional valve; and a third piston rod of the flameout cylinder is fixedly connected with a flameout switch of the diesel engine, and a third cylinder body of the flameout cylinder is hinged on a frame of the vehicle.

The invention has the advantages that: (1) the invention also comprises an electromagnetic directional valve, a water pipe component, a liquid level switch and a power supply; an air inlet P port of the electromagnetic directional valve is communicated with the air bag, an execution port A port of the electromagnetic directional valve is communicated with a rodless cavity of the butterfly valve cylinder, and a wiring terminal K of the electromagnetic directional valve is electrically connected with a power supply; the liquid level switch is arranged on the water pipe assembly and is connected in series in a connecting circuit between the electromagnetic reversing valve and the power supply, and when the water level at the liquid level switch is higher than a set value, the liquid level switch is switched on; therefore, when the vehicle runs on a heavy slope or downhill, the water level at the longitudinal pipe rises, when the water level at the liquid level switch in the longitudinal pipe rises to a set value, the liquid level switch is switched on, the terminal K of the electromagnetic directional valve is electrified, the port P of the air inlet of the electromagnetic directional valve is communicated with the port A of the execution port, the pressure gas in the air bag reaches the rodless cavity of the butterfly valve cylinder through the electromagnetic directional valve, the second piston rod of the butterfly valve cylinder drives the handle of the exhaust butterfly valve to rotate, so that the exhaust butterfly valve is in a closed state, namely, exhaust braking is automatically performed when the vehicle runs on the heavy slope. (2) The invention also comprises an electromagnetic directional valve, a water pipe component, a liquid level switch, a power supply, a first air control valve and a second air control valve; an air inlet P port of the electromagnetic directional valve is communicated with an air bag, an execution port A port of the electromagnetic directional valve is respectively communicated with an air control port K port of a first air control valve, an air control port K port of a second air control valve and a rodless cavity of a butterfly valve cylinder, the air inlet P port of the first air control valve is communicated with the air bag, and the execution port A port of the first air control valve is communicated with an air inlet P port of a manual directional valve; an execution port A and an execution port B of the manual reversing valve are respectively communicated with a rodless cavity and a rod cavity of the gear shifting cylinder, a first piston rod of the gear shifting cylinder is fixedly connected with a valve rod of the gear shifting operation valve, an air inlet port P of the second pneumatic control valve is communicated with the air bag, and an execution port A of the second pneumatic control valve is communicated with the rodless cavity of the gear shifting cylinder. Therefore, when the vehicle performs exhaust braking, the pressure gas in the gas bag simultaneously reaches the gas control port K of the first gas control valve and the gas control port K of the second gas control valve through the electromagnetic directional valve, so that the gas inlet P port of the first gas control valve is not communicated with the execution port A, and the gas inlet P port of the second gas control valve is communicated with the execution port A, so that the pressure gas in the gas bag cannot reach the manual directional valve through the first gas control valve and then reach the gear shifting cylinder, but the pressure gas in the gas bag can reach the rodless cavity of the gear shifting cylinder through the second gas control valve, and the vehicle can be automatically hung on the high-speed gear 3 during exhaust braking.

Drawings

FIG. 1 is a schematic diagram of the present invention;

FIG. 2 is a schematic view of the water tube assembly of the present invention mounted to the frame of a vehicle;

FIG. 3 is a schematic view of the water tube assembly of the present invention on a horizontal road;

fig. 4 is a schematic view of the water pipe assembly of the present invention when driving down a steep or downhill slope.

The reference numbers in the above figures are as follows: the gear shifting device comprises a manual reversing valve 1, a gear shifting cylinder 2, a first piston rod 2-1, a first cylinder body 2-2, a gear shifting operation valve 3, a first pneumatic control valve 4, an electromagnetic reversing valve 5, a second pneumatic control valve 6, a butterfly valve cylinder 7, a second piston rod 7-1, a second cylinder body 7-2, an exhaust butterfly valve 8, an air bag 9, a water pipe assembly 10, a transverse pipe 10-1, a longitudinal pipe 10-2, a liquid level switch 11, a switch detection pipe 11-1, a switch floating ball 11-2, a power supply 12, a third pneumatic control valve 13, a flameout cylinder 14, a third piston rod 14-1 and a third cylinder body 14-2.

Detailed Description

The invention is further described with reference to the following examples given in conjunction with the accompanying drawings:

as shown in fig. 1, the downhill automatic exhaust braking device for the vehicle comprises a manual reversing valve 1, a gear shifting cylinder 2, a gear shifting operation valve 3, a butterfly valve cylinder 7, an exhaust butterfly valve 8 and an air bag 9, and further comprises a first pneumatic control valve 4, an electromagnetic reversing valve 5, a second pneumatic control valve 6, a water pipe assembly 10, a liquid level switch 11 and a power supply 12; the water pipe assembly 10 comprises a transverse pipe 10-1 and a longitudinal pipe 10-2, the longitudinal pipe 10-2 is positioned at one end of the transverse pipe 10-1, the longitudinal pipe 10-2 is fixedly connected to the top wall of the transverse pipe 10-1, and the inner cavity of the transverse pipe 10-1 is communicated with the inner cavity of the longitudinal pipe 10-2; an air inlet P port of the electromagnetic directional valve 5 is communicated with an air bag 9, an execution port A port of the electromagnetic directional valve 5 is respectively communicated with an air control port K port of the first air control valve 4, an air control port K port of the second air control valve 6 and a rodless cavity of the butterfly valve cylinder 7, an air outlet T port of the electromagnetic directional valve 5 is communicated with the atmosphere, and a wiring terminal K of the electromagnetic directional valve 5 is electrically connected with a power supply 12; the liquid level switch 11 is arranged on a longitudinal pipe 10-2 of the water pipe assembly 10 and is connected in series in a connecting circuit between the electromagnetic directional valve 5 and the power supply 12, and a detection element of the liquid level switch 11 is inserted into the longitudinal pipe 10-2; the detection element comprises a switch detection tube 11-1 and a switch floating ball 11-2 which is sleeved on the switch detection tube 11-1 and can move on the switch detection tube 11-1. When the water level at the liquid level switch 11 is higher than a set value, the set value of the water level at the liquid level switch 11 is the water level value at the longitudinal pipe 10-2 when the vehicle runs on an uphill slope of 4 degrees through tests. The liquid level switch 11 is switched on, and a terminal K of the electromagnetic directional valve 5 is electrified; when the water level of a switch floating ball 11-2 of a liquid level switch 11 in the longitudinal pipe 10-2 is higher than a set value, the liquid level switch 11 is in a switch-on state; when the water level at the switch floating ball 11-2 of the liquid level switch 11 in the longitudinal pipe 10-2 is lower than a set value, the liquid level switch 11 is in an off state. Under normal conditions, the electromagnetic directional valve 5 is in a power-off state and is in a normally closed state, that is, the port P of the air inlet of the electromagnetic directional valve 5 is not communicated with the port a of the execution port, and when the terminal K of the electromagnetic directional valve 5 is powered on, the port P of the air inlet of the electromagnetic directional valve 5 is communicated with the port a of the execution port. The second cylinder body 7-2 of the butterfly valve cylinder 7 is hinged to a frame of a vehicle, and a second piston rod 7-1 of the butterfly valve cylinder 7 is fixedly connected with a handle 8-1 of an exhaust butterfly valve 8; when the rodless cavity of the butterfly valve cylinder 7 enters pressure gas, the second piston rod 7-1 of the butterfly valve cylinder 7 pushes the handle 8-1 of the exhaust butterfly valve 8 to rotate, so that the exhaust butterfly valve 8 is in a closed state, and the vehicle is in an exhaust braking state at the moment. An air inlet port P of the first pneumatic control valve 4 is communicated with an air bag 9, and an execution port A of the first pneumatic control valve 4 is communicated with an air inlet port P of the manual reversing valve 1; an execution port A and an execution port B of the manual reversing valve 1 are respectively communicated with a rodless cavity and a rod cavity of the gear shifting cylinder 2, and a gas outlet T port of the manual reversing valve 1 is communicated with the atmosphere; under normal conditions, the first pneumatic control valve 4 is in a normally open state, that is, the port P of the air inlet of the first pneumatic control valve 4 is communicated with the port a of the execution port, and when the port K of the first pneumatic control valve 4 enters pressure gas, the port P of the air inlet of the first pneumatic control valve 4 is not communicated with the port a of the execution port. When no rod cavity and rod cavity of the gear shifting cylinder 2 do not enter pressure gas, the gear of the vehicle is hung on the middle speed gear 2, and when the rod cavity of the gear shifting cylinder 2 enters pressure gas, the gear of the vehicle is hung on the low speed gear 1.

And an air inlet port P of the second pneumatic control valve 6 is communicated with an air bag 9, and an execution port A of the second pneumatic control valve 6 is communicated with a rodless cavity of the gear shifting cylinder 2. Under normal conditions, the second pneumatic control valve 6 is in a normally closed state, namely the air inlet port P of the first pneumatic control valve 4 is not communicated with the execution port A, and when pressure gas enters the control port K of the second pneumatic control valve 6, the air inlet port P of the second pneumatic control valve 6 is communicated with the execution port A.

The pneumatic control device also comprises a third pneumatic control valve 13 and a flameout cylinder 14; an air inlet port P of the third pneumatic control valve 13 is communicated with the air bag 9, an execution port A of the third pneumatic control valve 13 is communicated with a rod cavity of the flameout air cylinder 14, and a control port K of the third pneumatic control valve 13 is communicated with an execution port A of the electromagnetic directional valve 5; a third piston rod 14-1 of the flameout cylinder 14 is fixedly connected with a flameout switch of the diesel engine, and a third cylinder body 14-2 of the flameout cylinder 14 is hinged to a frame of the vehicle.

As shown in FIG. 2, in use, the water pipe assembly 10 is mounted on a frame 100 of a vehicle, and one end of the cross pipe 10-1 having the longitudinal pipe 10-2 is mounted on a head side of the vehicle, and one end of the cross pipe 10-1 not having the longitudinal pipe 10-2 is mounted on a tail side of the vehicle.

As shown in fig. 3, water is supplied to water tube assembly 10 to top wall AB of cross tube 10-1 of water tube assembly 10 by placing water tube assembly 10 in a horizontal state, so that cross tube 10-1 of water tube assembly 10 is filled with water.

As shown in figures 1 and 4, when the vehicle runs on a heavy slope or downhill, the water level line in the water pipe assembly 10 is the CD line in figure 4, the water level at the position of the longitudinal pipe 10-2 rises, when the water level at the position of the liquid level switch 11 in the longitudinal pipe 10-2 rises to a set value, the liquid level switch 11 is switched on, the terminal K of the electromagnetic directional valve 5 is electrified, the port P of the air inlet of the electromagnetic directional valve 5 is communicated with the port A of the execution port, the pressure gas in the air bag 9 reaches the rodless cavity of the butterfly valve cylinder 7 through the electromagnetic directional valve 5, the second piston rod 7-1 of the butterfly valve cylinder 7 drives the handle 8-1 of the exhaust butterfly valve 8 to rotate, so that the exhaust butterfly valve 8 is in a closed state, namely, exhaust braking is automatically performed. Meanwhile, the pressure gas in the gas bag 9 reaches a gas control port K of the first gas control valve 4 and a gas control port K of the second gas control valve 6 through the electromagnetic directional valve 5, so that a gas inlet P port of the first gas control valve 4 is not communicated with an execution port A, and a gas inlet P port of the second gas control valve 6 is communicated with the execution port A, so that the pressure gas in the gas bag 9 cannot reach the manual directional valve through the first gas control valve 4 and then reach the gear shifting cylinder 2, but the pressure gas in the gas bag 9 can reach a rodless cavity of the gear shifting cylinder 2 through the second gas control valve 6, and the vehicle is automatically engaged in a high-speed gear 3. The operation is very convenient.

When a vehicle runs on a small downhill road, a flat road or an uphill road, the water level at the position of a longitudinal pipe 10-2 is reduced, when the water level at the position of a liquid level switch 11 in the longitudinal pipe 10-2 is lower than a set value, the liquid level switch 11 is disconnected, a terminal K of an electromagnetic directional valve 5 loses electricity, a port P of an air inlet of the electromagnetic directional valve 5 is not communicated with a port A of an execution port, pressure gas in an air bag 9 cannot reach a rodless cavity of a butterfly valve cylinder 7 through the electromagnetic directional valve 5, the butterfly valve cylinder 7 is reset under the action of a spring, and a second piston rod 7-1 of the butterfly valve cylinder 7 drives a handle 8-1 of an exhaust butterfly valve 8 to rotate to enable the exhaust butterfly valve 8 to be in an open state, namely exhaust brake is; meanwhile, the pressure gas in the gas bag 9 can not reach the pneumatic control port K of the first pneumatic control valve 4 and the pneumatic control port K of the second pneumatic control valve 6 through the electromagnetic directional valve 5, so that the gas inlet P port of the first pneumatic control valve 4 is communicated with the execution port A, and the gas inlet P port of the second pneumatic control valve 6 is not communicated with the execution port A, so that the pressure gas in the gas bag 9 can reach the gas inlet P port of the manual directional valve 1 through the first pneumatic control valve 4, and the manual directional valve 1 is operated, so that the normal gear engaging operation can be carried out. At the same time, the pressure gas in the gas bag 9 cannot reach the rodless cavity of the shift cylinder 2 through the second pneumatic control valve 6.

When the diesel engine also comprises a third pneumatic control valve 13 and a flameout cylinder 14, a terminal K of the electromagnetic directional valve 5 is electrified, when an air inlet P port of the electromagnetic directional valve 5 is communicated with an execution port A port, pressure gas in the air bag 9 can reach a control port K port of the third pneumatic control valve 13 through the electromagnetic directional valve 5, so that the air inlet P port of the third pneumatic control valve 13 is communicated with the execution port A port, the pressure gas enters a rod cavity of the flameout cylinder 14, and a piston rod 14-1 of the flameout cylinder 14 drives a flameout switch of the diesel engine to act, so that the diesel engine is flameout. Therefore, the engine can be automatically turned off when exhaust braking is performed.