CN110615389A - Forklift lifting oil cylinder with up-down buffering function - Google Patents

Abstract

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 forklift lifting 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 communicating oil way which is communicated with the rod cavity and the rodless cavity all the time and a buffering oil way which plays a role of buffering, the piston is provided with a buffering cavity, a through hole and a stepped hole, and a one-way valve 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 is arranged in the cylinder cover; 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, hydraulic oil flows in from N rows of radial holes on the piston rod and acts on the one-way valve, and the one-way valve is opened to flow out; 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 piston buffer cavity, the rodless cavity is relatively closed at the moment, and hydraulic oil flows out from a gap formed by the buffer plunger and the buffer cavity.

Description

A forklift lifting cylinder with up and down cushioning

technical field

The invention relates to a hydraulic oil cylinder, in particular to a forklift lifting oil cylinder with up and down buffering.

Background technique

During the rapid movement of the hydraulic cylinder, strong impact, noise or even mechanical collision will be generated at the end of the stroke, especially in the case of high pressure, this effect is more obvious, which seriously affects the service life of the cylinder, so it must be finished at the end Perform proper buffering and braking before exercise to ensure the life of the hydraulic system and the cylinder. Commonly used buffers include in-cylinder buffering and out-of-cylinder buffering. However, out-of-cylinder buffering will increase the complexity of the entire hydraulic system and increase the The cost is relatively low, and the buffer structure in the cylinder is simple, the volume is small, and there is no need to add any additional hydraulic components such as flow control valves, which is an ideal buffer method.

Most of the existing forklift lifting cylinders have a structure with a lower buffer. This structure can only protect the lifting cylinder from buffering in the process of descending, so as to ensure that the piston and the cylinder head do not collide violently during the descending process. There are very few lifting cylinders with upper and lower buffers. The upper buffer used in the patent CN104595281M realizes throttling by processing a circle of small holes on the piston rod and slender holes on the piston. This buffer cannot produce gradual buffering, and the buffering effect is not good. Good, the process of machining elongated holes on the piston is difficult to realize, and this buffer cylinder is easily affected by oil pollution, so it is difficult to adjust the buffer.

Contents of the invention

The object of the present invention is to provide a forklift lifting buffer oil cylinder, which not only realizes up and down buffering, but also can solve the disadvantages of the current forklift lifting oil cylinder such as poor buffering effect, complicated processing technology, and easy to be affected by oil pollution.

In order to solve the above problems, the technical solution adopted by the present invention is: the forklift lifting cylinder with up and down buffering includes a cylinder assembly and a piston rod assembly, the cylinder assembly is composed of a cylinder head, a barrel and a cylinder head, and the piston The rod assembly consists of a piston and a piston rod. One end of the piston rod is connected to the piston, and the other end extends out of the cylinder from the cylinder head. The piston divides the internal space of the cylinder assembly into a rod chamber and a rodless chamber. The other end surface is provided with a stepped hole with a one-way valve; the end of the inlet and outlet oil passages of the cylinder head is connected with a cylindrical buffer plunger, and the inlet and outlet ports opened on the cylinder head are connected to the rodless cavity through the inner channel of the buffer plunger; The piston rod assembly is equipped with a communication oil circuit that always communicates with the rod chamber and the rodless chamber and a buffer oil circuit that acts as a buffer. In the cylinder head, there is a buffer sleeve that acts as a support and buffer near the rod chamber. In the present invention, when the piston rod assembly is moved to the vicinity of the cylinder head, the upper buffer sleeve closes the outlet of the connected oil circuit arranged in the rod cavity, and the buffer sleeve and the piston rod assembly form a relatively sealed cavity, and the hydraulic oil can only come from N rows on the piston rod close to the piston side radially flow into the small hole and act on the check valve. The check valve is opened by hydraulic oil pressure and flow out from the Unicom oil circuit. Due to the damping effect of the small hole and the check valve, the The outflow speed of the hydraulic oil in the rod cavity increases the pressure of the hydraulic oil in the rod cavity, thereby reducing the speed of the piston rod assembly at the end of the upward stroke, and realizing the upper buffer. When the piston rod assembly moves to the vicinity of the cylinder head, the buffer plunger on the cylinder head is inserted into the buffer chamber in the piston. At this time, the hydraulic oil in the rodless chamber can only flow out from the buffer gap formed by the buffer plunger and the buffer chamber. The buffer gap has a damping effect, which reduces the speed of the hydraulic oil flowing out of the rodless chamber and increases the pressure of the hydraulic oil in the rodless chamber, thereby reducing the speed of the piston rod assembly at the end of the downward stroke and realizing the downward buffering.

In the above-mentioned buffer oil cylinder, the piston is a stepped shaft, the first stepped shaft has a large diameter and matches with the cylinder, and the second stepped shaft has a small diameter and is socketed with the concave cavity in the piston rod; a buffer is provided in the center of the end face of the rodless cavity of the piston. A through hole is opened from the center of the other end face, and the through hole communicates with the buffer chamber. The diameter of the buffer chamber is larger than the diameter of the through hole. There are two steps, the diameter near the end face is large, and the diameter of the bottom of the stepped hole is small. An annular groove is formed on the outer surface of the second stepped shaft of the piston near the first stepped shaft, and a small radial hole is formed through the annular groove and the bottom of the stepped hole.

In the above buffer cylinder, the buffer gap is formed by the outer surface of the buffer plunger and the inner surface of the buffer chamber in the piston, and the buffer gap and the length of the buffer plunger can be changed to meet the buffer requirements under different working conditions.

In the above-mentioned buffer oil cylinder, a concave cavity is provided at the end connecting the piston rod and the piston, and the concave cavity is socketed with the second stepped shaft of the piston. The bottom of the concave cavity is provided with a large radial hole communicating with the rodless cavity. The number of holes and the size of the holes are appropriate to ensure the oil passage capacity of the rod cavity of the oil cylinder. The Unicom oil path is composed of a large radial hole, a cavity gap at the bottom of the piston rod, and a through hole; the front end of the cavity of the piston rod is provided with N row diameter To the small hole, the radial small hole runs through the cavity of the piston rod.

In the buffer oil cylinder mentioned above, the upper buffer oil is composed of N rows of radial small holes opened at the front end of the piston rod cavity, annular grooves on the surface of the second stepped shaft of the piston, radial small holes, and stepped holes, and the one-way valve is installed on the stepped In the hole, the one-way valve controls the flow of hydraulic oil from the rod cavity to the radial hole at the front end of the piston rod cavity, then flows to the annular groove, the radial hole, the stepped hole, and finally flows out from the through hole, and the reverse oil path is blocked. Gradual upper cushioning is realized through the distribution, number and size of radial small holes on the piston rod, the number of one-way valves in the piston, and the pre-compression force of the one-way valves.

Description of drawings

Fig. 1 is a sectional view of the lifting cylinder of the forklift of the present invention

Figure 2 Schematic diagram of the flow of buffer hydraulic oil under the buffer cylinder

Figure 3 Schematic diagram of the flow of buffer hydraulic oil on the buffer cylinder

Names and serial numbers of parts in the figure: cylinder head 1, cylinder 2, piston rod 3, rod chamber 4, large radial hole 5, check valve 6, N rows of radial small holes 7, piston 8, rodless chamber 9 , cylinder head 10, oil inlet and outlet 11, buffer plunger 12, buffer chamber 13, annular groove 14, radial small hole 15, cavity bottom clearance 16, through hole 17, buffer sleeve 18.

Detailed ways

The specific implementation will be described below in conjunction with the accompanying drawings.

As shown in Figure 1, the forklift lifting cylinder in this embodiment includes a cylinder body assembly and a piston rod assembly, the cylinder body assembly is composed of a cylinder head 1, a barrel 2 and a cylinder head 10, and the piston rod assembly is composed of a piston 8 forms with piston rod 3. One end of the piston rod 3 is connected to the piston 8, and the other end protrudes from the cylinder head 1 to the outside of the oil cylinder. The piston 3 divides the internal space of the cylinder assembly into a rod chamber 4 and a rodless chamber 9. There is a buffer chamber 13, and a cylindrical buffer plunger 12 is connected to the cylinder head 10. The oil inlet and outlet 11 opened on the cylinder head 3 are connected to the rodless chamber 9 through the internal channel of the buffer plunger 12; The connecting oil passage between the rod chamber 4 and the rodless chamber 9 and the buffer oil passage for buffering, and the buffer sleeve 18 for supporting and buffering in the cylinder head 1 near the rod chamber 4 . When the piston 8 moves to the vicinity of the cylinder head 1, the buffer sleeve 18 and the piston rod assembly form a relatively sealed cavity, and the hydraulic oil can only flow in from the N rows of radial holes 7 on the piston rod 3 near the piston side to act on it. On the one-way valve 6, the one-way valve 6 is opened by the pressure of the hydraulic oil to realize the upper buffer. Figure 3 is a schematic diagram of the flow of the hydraulic oil during the upper buffer. When the piston rod assembly moves to the vicinity of the cylinder head 10, the buffer plunger 12 on the cylinder head is inserted into the buffer chamber 13 in the piston, and the hydraulic oil can only flow out from the buffer gap formed by the buffer plunger 12 and the buffer chamber 13, realizing Lower buffering, Figure 2 is a schematic diagram of hydraulic oil flow during lower buffering.

As shown in Figure 1, the piston 8 is a stepped shaft, the first stepped shaft has a large diameter and matches the cylinder 2, and the second stepped shaft has a small diameter and fits into the concave cavity in the piston rod; the piston 8 is close to the side of the cylinder head 10 A buffer cavity 13 is set in the center of the end face, and a through hole 17 is opened in the center of the end face on the other side to communicate with the buffer cavity 13. On the same circumference on this side, M stepped holes equipped with check valves are evenly opened, and the outer surface of the second stepped shaft of the piston is close to the first An annular groove 14 is provided at a step, and a small radial hole 15 provided at the bottom of the stepped hole passes through the stepped hole and the annular groove 14 .

As shown in Figure 1, the buffer gap is formed by the outer surface of the buffer plunger 12 and the inner surface of the buffer chamber 13 in the piston. By changing the size of the buffer gap and the length of the buffer plunger 12, the buffer requirements under different working conditions can be met.

As shown in Figure 1, the end of the piston rod 3 connected to the second stepped shaft of the piston has a concave cavity, the concave cavity is socketed with the second stepped shaft of the piston, and the bottom of the concave cavity is provided with a hole that communicates with the rodless cavity. The large radial hole 5, the Unicom oil route is composed of the large radial hole 5, the concave cavity gap 16 at the bottom of the piston rod, and the through hole 17;

As shown in Figure 1, the upper buffer oil is composed of N rows of radial small holes 7, annular grooves 14, radial small holes 15, and one-way valve channels (stepped holes) opened at the front end of the piston rod cavity, wherein the one-way valve 6 is installed in the one-way valve channel (stepped hole). Gradual upper cushioning is realized by the distribution and number of radial small holes 7 on the piston rod 3 , the size of the radial small holes 7 , the number of 6 check valves in the piston, and the precompression force of the check valve 6 .

Claims (5)

1. The utility model provides a fork truck plays to rise hydro-cylinder with buffering from top to bottom, includes cylinder body subassembly and piston rod subassembly, the cylinder body subassembly comprises cylinder cap, a section of thick bamboo and cylinder head, the piston rod subassembly comprises piston and 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 end surface of the rodless cavity of the piston is provided with a buffer cavity, and the other end surface of the piston is provided with a step hole and a through hole which are provided with a one-way valve; the end parts 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 the rod cavity and the rodless cavity all the time and a buffering oil way which plays a role in buffering, and a buffering sleeve which plays a role in supporting and buffering is arranged in the cylinder cover close to the side of the rod cavity. When the piston moves to the position near the cylinder cover, the buffer sleeve and the piston rod assembly form a relatively sealed cavity, hydraulic oil can only flow in from N rows of radial small holes on the piston rod, which are close to the piston side, acts on the one-way valve, and the one-way valve is opened through hydraulic oil pressure to realize upper buffering. When the piston moves to the position near the cylinder head, the buffering plunger on the cylinder head is inserted into the buffering cavity in the piston, and hydraulic oil can only flow out from the buffering gap formed by the buffering plunger and the buffering cavity, so that lower buffering is realized.

2. A lifting cylinder as claimed in claim 1, wherein the piston is a stepped shaft, the first stepped shaft has a large diameter and is fitted with the cylinder barrel, and the second stepped shaft has a small diameter and is fitted with the cavity in the piston rod; the center of the end face of the rodless cavity of the piston is provided with a buffer cavity, the center of the other end face is provided with a through hole, the through hole is communicated with the buffer cavity, the diameter of the buffer cavity is larger than that of the through hole, M stepped holes for assembling the check valves are uniformly formed in the same circumference on the end face of the through hole of the piston, the stepped holes are provided with two steps, the diameter of the stepped holes close to the end face is large, the diameter of the bottom of each stepped hole is small, the outer surface of the second stepped shaft of the piston is close to the position close to the first stepped shaft and is provided with.

3. The 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 of the cavity at the bottom of the piston rod and a through hole; the front end part of the piston rod concave cavity is provided with N rows of radial small holes which penetrate through the piston rod concave cavity.

4. A lifting oil cylinder as claimed in claims 2 and 3, wherein the upper buffer oil passage is formed by N rows of radial small holes formed at the front end of the cavity of the piston rod, an annular groove on the surface of the second stepped shaft of the piston, radial small holes on the second stepped shaft of the piston, and stepped holes, and a check valve is installed in the stepped holes and controls the hydraulic oil to flow from the rod cavity to the radial small holes at the front end of the cavity of the piston rod, then to the annular groove, the radial small holes, and the stepped holes, and finally to flow out from the through holes, and the reverse oil passage is not communicated.

5. 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.