阅读说明：本技术 叉车缓冲起升油缸 (Fork truck buffering lifting oil cylinder ) 是由 刘彤 代振维 申俊 于 2018-11-16 设计创作，主要内容包括：本发明涉及液压油缸,为解决叉车起升油缸上下缓冲问题。油缸由缸体组件和活塞杆组件组成,活塞杆组件由活塞杆和活塞组成,活塞将油缸内部空间隔成有杆腔和无杆腔,活塞杆组件开设始终联通有杆腔和无杆腔的联通油路,活塞内开设有缓冲腔、贯通孔、阶梯孔,阶梯孔内安装顶杆；缸体组件由缸盖、筒和缸头组成,缸盖内靠近有杆腔侧有起支撑和缓冲作用的缓冲套；活塞杆组件移至缸盖附近时,缓冲套封闭联通油路位于有杆腔内的出口,缸盖把顶杆顶开,有杆腔内的液压油从顶杆和阶梯孔内的间隙流出；活塞杆组件移至缸头附近时,缸头上的缓冲柱塞插入活塞的缓冲腔内,无杆腔此时相对封闭,液压油只能从缓冲柱塞与缓冲腔形成的间隙流出。(The invention relates to a hydraulic oil cylinder, and aims to solve the problem of up-and-down buffering of a lifting oil cylinder of a forklift. The oil cylinder consists of a cylinder body assembly and a piston rod assembly, the piston rod assembly consists of a piston rod and a piston, the piston divides the inside space of the oil cylinder into a rod cavity and a rodless cavity, the piston rod assembly is provided with a communicated oil circuit which is communicated with the rod cavity and the rodless cavity all the time, the piston is internally provided with a buffer cavity, a through hole and a stepped hole, and an ejector rod is arranged in the stepped hole; the cylinder body component consists of a cylinder cover, a cylinder and a cylinder head, and a buffer sleeve for supporting and buffering is arranged in the cylinder cover and close to the rod cavity side; when the piston rod assembly moves to the position near the cylinder cover, the buffer sleeve seals an outlet of the communicating oil way in the rod cavity, the cylinder cover pushes the ejector rod open, and hydraulic oil in the rod cavity flows out from a gap between the ejector rod and the stepped hole; when the piston rod assembly moves to the position near the cylinder head, the buffering plunger on the cylinder head is inserted into the buffering cavity of the piston, the rodless cavity is relatively closed at the moment, and hydraulic oil can only flow out from a gap formed by the buffering plunger and the buffering cavity.)

1. The forklift buffering lifting oil cylinder comprises a cylinder body assembly and a piston rod assembly, wherein the cylinder body assembly consists of a cylinder cover, a cylinder and a cylinder head, the piston rod assembly consists of a piston and a piston rod, the piston rod assembly is provided with a communicated oil way communicated with a rod cavity and a rodless cavity all the time, one end of the piston rod is connected with the piston, the other end of the piston rod extends out of the oil cylinder from the cylinder cover, the piston divides the inner space of the cylinder body assembly into the rod cavity and the rodless cavity, the piston is provided with a buffering cavity close to the center of the end face of the side end face of the cylinder head and is provided with an axial step hole on the same circumference of; a buffer sleeve for supporting and buffering is arranged in the cylinder cover close to the rod cavity; the end surfaces of the oil passage at the inlet and the outlet of the cylinder head are connected with a cylindrical buffer plunger, and an oil inlet and an oil outlet which are formed on the cylinder head are connected with the rodless cavity through an internal passage of the buffer plunger; when the piston rod assembly moves to the position near the cylinder cover, the buffer sleeve seals an outlet of the communicating oil path in the rod cavity, the ejector rod is in contact with the cylinder cover, the cylinder cover pushes the ejector rod open, and hydraulic oil in the rod cavity flows out from a gap between the ejector rod and the stepped hole; when the piston rod assembly moves to the position near the cylinder head, the cylindrical buffer plunger on the cylinder head is inserted into the buffer cavity of the piston, the rodless cavity is relatively closed at the moment, and hydraulic oil can only flow out from the buffer gap formed by the buffer plunger and the buffer cavity.

2. The piston of claim 1, wherein the piston is a stepped shaft, the first stepped shaft has a large diameter and is fitted to the barrel, the second stepped shaft has a small diameter and is fitted to a cavity in the piston rod, a buffer chamber is formed in the center of the end surface on the side of the piston cylinder head and N axial stepped holes are formed in the same circumference of the end surface, a through hole is formed in the center of the other end surface of the piston, the through hole communicates with the buffer chamber, and the diameter of the buffer chamber is larger than the diameter of the through hole.

3. A lifting oil cylinder as claimed in claim 1 or 2, wherein the stepped hole passes through the first stepped shaft of the piston, the stepped hole has two steps, the stepped hole on the side of the rodless chamber is largest, the stepped hole on the side of the rod chamber is smallest, the stepped hole is provided with a spring seat, a spring and a push rod in sequence from the side of the rodless chamber to the side of the rod chamber, and the push rod extends out of the stepped hole to the rod chamber.

4. A lifting cylinder as claimed in claim 3, wherein the lift pin includes a slender shaft, a cone and a short shaft, the spring seat is provided with an axial through hole, the diameter of the smallest hole of the stepped hole of the piston is larger than the diameter of the slender shaft of the lift pin and smaller than the maximum diameter of the cone, one end of the spring presses the lift pin to press the conical surface of the lift pin on the step of the stepped hole, the other end of the spring presses the spring seat, and the spring seat is connected with the stepped hole by screw.

5. A lifting oil cylinder as claimed in claim 1 or 2, wherein the end of the piston rod connected to the piston is provided with a cavity, the cavity is sleeved with the second step shaft of the piston, the bottom of the cavity is provided with a large radial hole communicated with the rod cavity, and the communicated oil path is composed of the large radial hole, a gap between the cavities at the bottom of the piston rod and a through hole.

6. A lifting cylinder as claimed in claim 1, wherein the buffer plunger is located in the rodless chamber of the cylinder, and the buffer gap during the lower buffering process is formed by a gap formed by the outer surface of the buffer plunger and the inner surface of the piston buffer chamber.

Technical Field

The invention relates to a hydraulic oil cylinder, in particular to a forklift buffer lifting oil cylinder.

Background

In the process of rapid movement of the hydraulic cylinder, strong impact, noise and even mechanical collision can be generated at the stroke end, particularly under the condition of high pressure, the impact is more obvious, the service life of the hydraulic cylinder is seriously influenced, therefore, proper buffering and braking must be carried out before the movement is finished to ensure the service lives of a hydraulic system and the hydraulic cylinder, generally common buffering comprises in-cylinder buffering and out-cylinder buffering, however, the out-cylinder buffering can increase the complexity of the whole hydraulic system and the cost of the whole hydraulic system, the in-cylinder buffering has a simple structure and small volume, and no additional hydraulic elements such as any flow control valve are needed to be added, so that the hydraulic cylinder is an ideal buffering mode.

Most of existing forklift lifting oil cylinders are of structures with lower buffers, and the structures can only protect the lifting oil cylinders from buffering in the descending process and ensure that severe impact between pistons and cylinder heads does not occur in the descending process. The play to rise hydro-cylinder of buffering about the area is very few, and the buffering is realized the throttle through processing on the piston rod round aperture and the piston elongate hole in the last buffering that patent CN104595281M adopted, and this kind of buffering can not produce the buffering of gradual change, and the buffering effect is not good, and the difficult realization of processing elongate hole technology on the piston to this buffer cylinder receives the greasy dirt easily, hardly adjusts the buffering.

Disclosure of Invention

The invention aims to provide a buffer oil cylinder which not only realizes up-down buffering, but also can overcome the defects of poor up-down buffering effect, complex processing technology, complex structure, easy influence of oil stains and the like of the existing forklift lifting oil cylinder.

In order to solve the problems, the invention adopts the technical scheme that: the forklift buffering lifting oil cylinder comprises a cylinder body assembly and a piston rod assembly, wherein the cylinder body assembly comprises a cylinder cover, a cylinder and a cylinder head, and the piston rod assembly comprises a piston and a piston rod. One end of the piston rod is connected with the piston, the other end of the piston rod extends out of the oil cylinder from the cylinder cover, the piston divides the inner space of the cylinder body assembly into a rod cavity and a rodless cavity, the center of the piston, which is close to the end face of the cylinder head, is provided with a buffer cavity, the same circumference of the end face is provided with an axial step hole, and a push rod is arranged in the step hole; a buffer sleeve for supporting and buffering is arranged in the cylinder cover close to the rod cavity; the end surfaces of the oil passage at the inlet and the outlet of the cylinder head are connected with a cylindrical buffer plunger, and an oil inlet and an oil outlet which are formed on the cylinder head are connected with the rodless cavity through an internal passage of the buffer plunger; the piston rod assembly is provided with a communicating oil way which is communicated with a rod cavity and a rodless cavity all the time. According to the invention, when the piston rod assembly moves to the vicinity of the cylinder cover, the buffer sleeve seals the outlet of the communicating oil path in the rod cavity, the ejector rod is contacted with the cylinder cover, the ejector rod is ejected by the cylinder cover, the hydraulic oil in the rod cavity flows out from the gap between the ejector rod and the stepped hole, and due to the damping action of the gap, the pressure of the ejector rod and the hydraulic oil in the rodless cavity and the like, the outflow speed of the hydraulic oil in the rod cavity is reduced, the pressure of the hydraulic oil in the rod cavity is improved, so that the speed of the piston rod assembly when the ascending stroke is ended is reduced, and the upper buffer. When the piston rod assembly moves to the position near the cylinder head, the cylindrical buffer plunger on the cylinder head is inserted into the buffer cavity of the piston, the rodless cavity is relatively closed at the moment, hydraulic oil can only flow out of the buffer gap formed by the buffer plunger and the buffer cavity, the buffer gap has a damping effect, the speed of the hydraulic oil flowing out of the rodless cavity is reduced, the hydraulic oil pressure of the rodless cavity is improved, the speed of the piston rod assembly when the lifting stroke is ended is reduced, and lower buffering is achieved.

In the buffer oil cylinder, the piston is a stepped shaft, the diameter of the first stepped shaft is large and is matched with the cylinder, and the diameter of the second stepped shaft is small and is sleeved with the concave cavity in the piston rod; the center of the side end face of the piston cylinder head is provided with a buffer cavity, N axial stepped holes are formed in the same circumference of the side end face, a through hole is formed in the center of the other end face of the piston, the through hole is communicated with the buffer cavity, the diameter of the buffer cavity is larger than that of the through hole, and the stepped holes are guaranteed not to be communicated with the through hole and the buffer cavity.

In the buffer oil cylinder, the stepped hole penetrates through the first stepped shaft of the piston, the stepped hole is provided with two steps, the stepped hole on the side of the rodless cavity is the largest, the stepped hole on the side of the rod cavity is the smallest, the stepped hole is sequentially provided with the spring seat, the spring and the ejector rod from the side of the rodless cavity to the side of the rod cavity, and the ejector rod extends out of the stepped hole to the rod cavity.

In the buffer oil cylinder, the ejector rod comprises the characteristics of a slender shaft, a cone, a short shaft and the like, the spring seat is provided with an axial through hole, the aperture of the minimum hole of the stepped hole of the piston is larger than the diameter of the slender shaft of the ejector rod and smaller than the maximum diameter of the cone, one end of the spring compresses the ejector rod, the conical surface of the ejector rod is compressed on the step of the stepped hole, the spring seat is compressed at the other end of the spring, the spring seat is in threaded connection with the stepped hole, and the buffer effect in the buffer process is adjusted by adjusting the equivalent value of the number of the stepped holes, the minimum aperture of the.

In the buffer oil cylinder, the end part of the piston rod connected with the piston is provided with a concave cavity, the concave cavity is sleeved with the second stepped shaft of the piston, the bottom of the concave cavity is provided with a large radial hole communicated with the rod cavity, the number and the size of the large radial hole are suitable for ensuring the oil passing capacity of the oil cylinder with the rod cavity, and the communicated oil way is composed of the large radial hole, a gap of the concave cavity at the bottom of the piston rod and a through hole.

In the buffer oil cylinder, the buffer gap is formed by the outer surface of the buffer plunger and the inner surface of the buffer cavity in the piston, and the buffer requirements under different working conditions are met by changing the size of the buffer gap and the length of the buffer plunger.

Drawings

FIG. 1 is a cross-sectional view of a forklift buffer lifting cylinder of the present invention

FIG. 2 schematic view of the flow of the lower buffer hydraulic oil of the buffer cylinder

FIG. 3 is a schematic view of buffer hydraulic oil flow on the buffer cylinder

Part names and serial numbers in the figure: the cylinder cover comprises a cylinder cover 1, a cylinder 2, a piston rod 3, a rod cavity 4, a large radial hole 5, a through hole 6, a buffer cavity 7, a mandril 8, a piston 9, a stepped hole 10, a spring 11, a spring seat 12, a rodless cavity 13, an oil inlet and outlet 14, a cylinder head 15, a buffer plunger 16, a cavity bottom gap 17 and a buffer sleeve 18.

Detailed Description

The following description of the embodiments refers to the accompanying drawings.

As shown in fig. 1, the forklift buffer lifting cylinder in the embodiment includes a cylinder body assembly composed of a cylinder cover 1, a cylinder 2 and a cylinder head 15, and a piston rod assembly composed of a piston 9 and a piston rod 3. One end of the piston rod 3 is connected with a piston 9, the other end of the piston rod extends out of the oil cylinder from the cylinder cover 1, the piston 9 divides the inner space of the cylinder body assembly into a rod cavity 4 and a rodless cavity 13, the piston 9 is provided with a buffer cavity 7 close to the center of the end face of the cylinder head 15 side, the same circumference of the end face is provided with an axial step hole 10, and a mandril 8 is arranged in the step hole 10; a buffer sleeve 18 for supporting and buffering is arranged in the cylinder cover 1 and close to the rod cavity 4; a cylindrical buffer plunger 16 is connected to the end surfaces of the inlet and outlet oil ducts of the cylinder head 15, and an oil inlet and outlet 14 formed in the cylinder head 15 is connected with the rodless cavity 13 through an internal channel of the buffer plunger 16; the piston rod assembly concerned is provided with a communicating oil way which is communicated with the rod cavity 4 and the rodless cavity 13 all the time. When the piston rod assembly moves to the position near the cylinder cover 1, the buffer sleeve 18 seals an outlet of the communicated oil path in the rod cavity, the ejector rod 8 is in contact with the cylinder cover 1, the ejector rod 8 is ejected by the cylinder cover 1, hydraulic oil in the rod cavity 4 flows out from a gap between the ejector rod 8 and the stepped hole 10, the upper buffer of the oil cylinder is realized, and fig. 3 is a schematic diagram of buffer hydraulic oil flowing on the oil cylinder. When the piston rod assembly moves to the position near the cylinder head 15, the cylindrical buffer plunger 16 on the cylinder head 15 is inserted into the buffer cavity 7 of the piston, the rodless cavity 13 is relatively closed at the moment, hydraulic oil can only flow out from a buffer gap formed by the buffer plunger 16 and the buffer cavity 7, and the buffer under the oil cylinder is realized, and fig. 2 is a schematic flow diagram of the buffer hydraulic oil under the oil cylinder.

As shown in fig. 1, the piston 9 is a stepped shaft, the first stepped shaft has a large diameter and is matched with the cylinder 2, and the second stepped shaft has a small diameter and is sleeved with a concave cavity in the piston rod 3; the center of the end face of the piston 9 on the cylinder head side is provided with a buffer cavity 7, 3 axial stepped holes 10 are arranged on the same circumference of the end face, the center of the other end face of the piston 9 is provided with a through hole 6, the through hole 6 is communicated with the buffer cavity 7, and the diameter of the buffer cavity 7 is larger than that of the through hole 6.

As shown in fig. 1, a stepped hole 10 penetrates through a first stepped shaft of a piston 9, the stepped hole 10 has two steps, a spring seat 12, a spring 11 and a ram 8 are sequentially installed in the stepped hole 10 from a rodless chamber 13 side to a rod chamber 4 side, and the ram 8 extends out of the stepped hole 10 into the rod chamber 4.

As shown in fig. 1, the ejector rod 8 includes features of a slender shaft, a cone, a short shaft, etc., the spring seat 12 is provided with an axial through hole, a fit clearance exists between the minimum hole of the piston stepped hole 10 and the slender shaft of the ejector rod 8 in a fit manner, one end of the spring 11 compresses the ejector rod 8 to compress the conical surface of the ejector rod 8 on the step of the stepped hole 10, the other end of the spring 11 compresses the spring seat 12, and the spring seat 12 is in threaded connection with the stepped hole 10.

As shown in fig. 1, a concave cavity is formed at the end part of the piston rod 3 connected with the piston 9, the concave cavity is sleeved with the second stepped shaft of the piston 9, a large radial hole 5 communicated with the rod cavity 4 is formed at the bottom of the concave cavity, and the communicated oil path is composed of the large radial hole 5, a gap 17 of the concave cavity at the bottom of the piston rod and a through hole 6.

As shown in fig. 1, the damping plunger 16 is located in the rodless chamber 13 of the cylinder, and the damping gap in the lower damping process is formed by a gap formed by the outer surface of the damping plunger 16 and the inner surface of the damping chamber 7.

The embodiments described in this specification are merely illustrative of implementations of the inventive concept and the scope of the present invention should not be considered limited to the specific forms set forth in the embodiments but includes equivalent technical means as would be recognized by those skilled in the art based on the inventive concept.