阅读说明：本技术 组合式凸轮轴 (Combined camshaft ) 是由 张凤武 于 2018-08-30 设计创作，主要内容包括：本发明提供一种组合式凸轮轴,其包括：芯轴,具有轴向延伸的轴孔；凸轮和传动单元,套设在所述芯轴上且与所述芯轴胀紧固定；堵头,压设在所述轴孔的端口内；传动单元位于芯轴的一端,堵头与传动单元共同作为组合式凸轮轴动力输入的接口部。本发明采用在芯轴的轴孔端部压入堵头,使堵头在对传动单元起支撑作用的同时,并且与传动单元可直接作为凸轮轴动力输入的接口部,无需再有连接传动法兰等过渡部件,简化了发动机的传动机构。(The present invention provides a combined camshaft, which comprises: a mandrel having an axially extending shaft bore; the cam and the transmission unit are sleeved on the mandrel and are expanded and fixed with the mandrel; the plug is pressed in the port of the shaft hole; the transmission unit is positioned at one end of the mandrel, and the plug and the transmission unit are jointly used as an interface part for power input of the combined camshaft. The invention adopts the mode that the end part of the shaft hole of the mandrel is pressed into the plug, so that the plug can directly serve as a connecting part for power input of the camshaft with the transmission unit while supporting the transmission unit, and transition parts such as a connecting transmission flange and the like are not needed, thereby simplifying the transmission mechanism of the engine.)

1. A composite camshaft, comprising:

a mandrel having an axially extending shaft bore;

the cam and the transmission unit are sleeved on the mandrel and are expanded and fixed with the mandrel;

the plug is pressed in the port of the shaft hole;

the transmission unit is positioned at one end of the mandrel, and the plug and the transmission unit are jointly used as an interface part for power input of the combined camshaft.

2. The assembled camshaft according to claim 1, wherein: the mandrel is provided with a matching section for positioning the cam and the transmission unit, the cross section profiles of the peripheral surfaces of the matching sections at any axial position are the same, and the cross section profiles comprise: the device comprises a linear area and an arc area, wherein the linear area belongs to a polygon and comprises a plurality of sections of straight lines, and the arc area belongs to a circle and comprises a plurality of sections of arcs.

3. The assembled camshaft according to claim 2, wherein: the cross-sectional profile of the inner circumferential surface of the cam at the axial position is consistent with the cross-sectional profile of the outer circumferential surface of the matching section of the mandrel.

4. The assembled camshaft according to claim 2, wherein: the cross-sectional profile of the inner circumferential surface of the transmission unit at the axial position is consistent with the cross-sectional profile of the outer circumferential surface of the matching section of the mandrel.

5. The assembled camshaft according to claim 2, wherein: the number of sides of the polygon is a multiple of the number of engine cylinders N.

6. The assembled camshaft according to claim 1, wherein: and machining the outer surface of the mandrel at intervals to form cylindrical sections, wherein the cylindrical sections are journals of the mandrel, and the journals are used for rotating and supporting the camshaft.

7. The assembled camshaft according to claim 6, wherein: the mandrel is provided with a matching section for positioning the cam and the transmission unit, and the outer diameter of the matching section is larger than that of the cylindrical section.

8. The assembled camshaft according to claim 1, wherein: and one end of the plug inserted into the mandrel is provided with an outer cylindrical surface, and knurling is performed on the outer cylindrical surface.

Technical Field

The invention relates to the field of automobile engines, in particular to a combined camshaft.

Background

The camshaft is one of the key transmission components of an automotive engine, and directly influences the performance of the engine. At present, the method for manufacturing the camshaft is as follows: the traditional integral casting method and forging method, and a combined method for manufacturing the camshaft. Among them, the casting method and the forging method are used to manufacture the camshaft, and have many disadvantages, such as: the performance maximization design and utilization can not be carried out to each position of camshaft, and the performance requirement to each part such as cam, axle journal, dabber, drive unit has very big difference, if with single material, can not accomplish the maximize to the performance of every part, and whole manufacturing process is complicated, needs a large amount of machining processes, and production efficiency is not high, wastes time and energy, and the cost is too high to, the energy consumption is big, environmental pollution is serious.

The manufacturing method of the combined camshaft comprises the following steps: welding, sintering, expanding, shrink-fitting, mechanical knurling, and the like. The methods are that the camshaft is decomposed into a single cam part, an intermediate mandrel part, a transmission part and the like, and then different manufacturing methods are applied to connect the parts to form the camshaft.

In addition, the conventional assembled camshaft has different transmission part forms, some assembled camshafts need to additionally increase a transition part and have insufficient connection strength, and therefore, an assembled camshaft capable of directly introducing power is required.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention provides a combined camshaft, which is used to solve the problems of the prior art that the power input part of the combined camshaft has a complicated structure and the connection strength of the power input end part is insufficient.

To achieve the above and other related objects, the present invention provides a combined camshaft including:

a mandrel having an axially extending shaft bore;

the cam and the transmission unit are sleeved on the mandrel and are expanded and fixed with the mandrel;

the plug is pressed in the port of the shaft hole;

the transmission unit is positioned at one end of the mandrel, and the plug and the transmission unit are jointly used as an interface part for power input of the combined camshaft.

Preferably, the mandrel has a matching section for positioning the cam and the transmission unit, and the cross-sectional profile of the outer peripheral surface of the matching section at any axial position is the same, and the cross-sectional profile includes: the device comprises a linear area and an arc area, wherein the linear area belongs to a polygon and comprises a plurality of sections of straight lines, and the arc area belongs to a circle and comprises a plurality of sections of arcs.

Preferably, the cross-sectional profile of the inner peripheral surface of the cam at the axial position coincides with the cross-sectional profile of the outer peripheral surface of the engagement section of the mandrel.

Preferably, the cross-sectional profile of the inner circumferential surface of the transmission unit at the axial position is in accordance with the cross-sectional profile shape of the outer circumferential surface of the engagement section of the mandrel.

Preferably, the number of sides of the polygon is a multiple of the number of engine cylinders N.

Preferably, cylindrical sections are machined on the outer surface of the mandrel at intervals, and the cylindrical sections are journals of the mandrel, which are used for rotating and supporting the camshaft.

Preferably, the mandrel is provided with a matching section for positioning the cam and the transmission unit, and the outer diameter of the matching section is larger than that of the cylindrical section.

Preferably, one end of the plug inserted into the mandrel is provided with an outer cylindrical surface, and knurling is performed on the outer cylindrical surface.

As described above, the assembled camshaft of the present invention has the following advantageous effects: the end part of the shaft hole of the mandrel is pressed into the plug, so that the plug can directly serve as a connecting part for power input of the camshaft with the transmission unit while supporting the transmission unit, transition parts such as a transmission flange and the like are not required to be connected, and the transmission mechanism of the engine is simplified.

Drawings

Fig. 1 is a schematic view showing an embodiment of an assembled camshaft according to the present invention.

Fig. 2 shows a sectional view of another embodiment of an assembled camshaft according to the present invention.

Figure 3 shows a schematic view of a mandrel according to the invention.

Figure 4 shows a schematic cross-sectional view of a mandrel of the present invention.

Fig. 5 shows a schematic view of the cam of the present invention.

Fig. 6 shows a schematic view of the transmission unit of the present invention.

Fig. 7 is a schematic view of the plug of the present invention.

Description of the element reference numerals

10 core shaft

101 mating segment

10a straight line region

10b arc zone

11 axle hole

20 cam

20a straight line region

20b arc area

30. 50 plug

40 Transmission Unit

60 journal

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

Please refer to fig. 1 to 7. It should be understood that the structures, ratios, sizes, and the like shown in the drawings are only used for matching the disclosure of the present disclosure, and are not used for limiting the conditions that the present disclosure can be implemented, so that the present disclosure is not limited to the technical essence, and any structural modifications, ratio changes, or size adjustments should still fall within the scope of the present disclosure without affecting the efficacy and the achievable purpose of the present disclosure. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention.

As shown in fig. 1 and 2, the present invention provides a combined camshaft, which includes:

a mandrel 10 having an axially extending shaft hole 11;

the cam 20 and the transmission unit 40 are sleeved on the mandrel 10 and are expanded and fixed with the mandrel 10;

the plugs 30 and 50 are pressed in the ports of the shaft holes 11;

the transmission unit 40 is located at one end of the mandrel 10, and the plug 50 and the transmission unit 40 together serve as an interface for power input of the assembled camshaft.

The end part of the shaft hole of the mandrel is pressed with the plug, so that the plug can directly serve as a power input interface part of the camshaft with the transmission unit while supporting the transmission unit, and transition parts such as a transmission flange and the like are not required to be connected, the connection strength of the power input end part is improved, and the transmission mechanism of the engine is simplified.

As shown in fig. 2, 3 and 4, in the present embodiment, the mandrel 10 has a fitting section 101 for positioning the cam and the transmission unit, and the cross-sectional profiles of the outer peripheral surfaces of the fitting section 101 at any axial position are the same, and the cross-sectional profiles include: the straight line area 10a and the circular arc area 10b, the straight line area 10a belongs to a polygon and includes a plurality of sections of straight lines, and the circular arc area 10b belongs to a circle and includes a plurality of sections of circular arcs. In this embodiment, as shown in fig. 4, the polygon is a dodecagon

Fig. 2 shows an exemplary assembled camshaft with six cams 20, each cam 20 of the assembled camshaft corresponding to a cylinder of an engine, each cam 20 being connected in a rotationally fixed manner to the spindle 10 and rotating synchronously. Each cam 20 is used to actuate a different engine valve.

As shown in fig. 5, the cross-sectional profile of the inner peripheral surface of the cam 20 at an axial position is identical in shape to the cross-sectional profile of the outer peripheral surface of the engagement section of the mandrel 10. As shown in fig. 6, the cross-sectional profile of the inner circumferential surface of the transmission unit 40 at an axial position is in accordance with the cross-sectional profile of the outer circumferential surface of the engagement section of the mandrel 10. The corresponding cross-sectional profiles of the transmission unit 40 and the cam 20 include: the cross-sectional profile of the light-emitting diode comprises a linear area 20a and an arc area 20b, wherein the arc area 20b belongs to a circle and comprises a plurality of sections of arcs, the linear area 20a belongs to a polygon and comprises a plurality of sections of straight lines, and the straight lines and the arcs are arranged in a staggered mode along the circumferential direction and are connected into the cross-sectional profile. In which fig. 5 only the part of the rectilinear 20a and circular 20b sections of the cam 20 is indicated.

For the matching section 101 on the mandrel 10, when the cam 20 is sleeved on the matching section 101, the circular arc area 10b can match with the circular arc area 20b of the inner hole of the cam 20. Specifically, the circular arc region 10b is shaped to coincide with the circular arc region 20b of the inner hole of the cam 20, so that the circular arc region 10b (fig. 4) of the outer peripheral surface of the mandrel 10 is fitted with the circular arc region 20b (fig. 5) of the inner hole of the cam 20.

Therefore, the outline of the outer peripheral surface of the mandrel 10 in the scheme comprises the linear areas and the arc areas which are arranged in a staggered mode, the linear areas belong to the same polygon, and the arc areas belong to the same circle. When the cam is matched, the circular arc area and the corresponding circular arc area of the inner hole of the cam are matched to realize concentric assembly, and the linear area and the corresponding linear area of the inner hole of the cam are matched to realize fixed and anti-rotation connection. Compared with the existing camshaft adopting knurling combined connection and other combined connection modes, the camshaft has the advantages of larger transmitted torque and simpler structure.

The circle of the circular arc area 10b (or 20b) is concentric with the polygon of the straight line section 10a (or 20a), i.e. the geometric centers of the two are coincident. The number of sides of the polygon is a multiple of the number of engine cylinders N.

Machining the outer surface of the mandrel 10 at intervals to form cylindrical sections, wherein the cylindrical sections are journals 60 of the mandrel 10, and the journals 60 are used for rotating and supporting a camshaft; in addition, in the present embodiment, the cylindrical section (i.e., the journal 60) is in arc transition connection with the arc area and the linear area of the fitting section 101, so as to reduce stress concentration. More preferably, the outer diameter of the fitting section 101 is larger than the outer diameter of the cylindrical section.

Referring to fig. 7, in this embodiment, one end of the plug 30, 50 inserted into the mandrel 10 has an outer cylindrical surface, the diameter of the outer cylindrical surface is slightly larger than the inner diameter of the shaft hole 11 of the mandrel, and knurling is performed on the outer cylindrical surface. After the cam 20, the transmission unit 40 and the mandrel 10 are expanded and fastened into a whole, the plug 30 and the plug 50 are pressed into inner holes at two ends of the mandrel. The end cap 30 after knurling processing can be well in press fit with the inner wall of the mandrel, the transmission unit 40 is supported, the connection strength of the power input end portion is improved, the end cap is provided with a supporting portion exposed out of the mandrel and meets the requirement of being used as a power input connecting portion together with the transmission unit 40, when the camshaft is used, when engine power is input into the camshaft, a part for inputting power from the engine is located through the end cap (namely the supporting portion of the end cap), then the flange plate is connected to conduct power connection and transmission, and other transition elements do not need to be connected.

In summary, according to the combined camshaft of the present invention, the end cap is pressed into the shaft hole of the mandrel, so that the end cap supports the transmission unit, the connection strength of the power input end is improved, and the combined camshaft and the transmission unit can be directly used as the power input interface of the camshaft, without connecting transition components such as a transmission flange, and the transmission mechanism of the engine is simplified. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.