CN209740629U - Up-down buffering forklift lifting oil cylinder with feedback adjustment function - Google Patents
Up-down buffering forklift lifting oil cylinder with feedback adjustment function Download PDFInfo
- Publication number
- CN209740629U CN209740629U CN201821996481.6U CN201821996481U CN209740629U CN 209740629 U CN209740629 U CN 209740629U CN 201821996481 U CN201821996481 U CN 201821996481U CN 209740629 U CN209740629 U CN 209740629U
- Authority
- CN
- China
- Prior art keywords
- piston
- cavity
- hole
- cylinder
- oil
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Fluid-Damping Devices (AREA)
Abstract
The utility model relates to a hydraulic cylinder, in particular to an upper and lower buffering forklift lifting oil cylinder with feedback adjustment, which comprises a cylinder body component and a piston rod component, wherein the piston rod component comprises a piston rod and a piston, the piston divides the inner space of the oil cylinder into a rod cavity and a rodless cavity, the piston rod component is provided with a communicating oil circuit and an upper buffering oil circuit which are communicated with the rod cavity and the rodless cavity all the time, the piston is internally provided with a buffering cavity, a feedback oil circuit, a through hole and a stepped hole, and a main valve core 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 a cylinder cover, the buffer sleeve seals an oil outlet of the communicating oil way in the rod cavity, hydraulic oil acts on the end face of the bottom of the main valve core through a feedback oil way on the piston to push the main valve core to move, and an upper buffer oil way is opened; when the piston rod assembly moves to the position near the cylinder head, the buffering plunger on the cylinder head is inserted into the piston buffering cavity to form clearance throttling.
Description
Technical Field
The invention relates to a hydraulic oil cylinder, in particular to an up-down buffering forklift lifting oil cylinder with feedback regulation.
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 lifting oil cylinders with the upper and lower buffers are very few, the CN104595281M patent is an oil cylinder with the upper and lower buffer effects, the upper buffer adopted by the patent is realized by processing a circle of small holes on a piston rod and processing a slender hole on the piston, the pressure change in a buffer cavity is severe, the automatic feedback adjustment in the buffer process can not be realized according to the pressure change in the buffer cavity, and the buffer effect is not ideal.
Disclosure of Invention
The invention aims to provide an up-down buffering forklift lifting buffering oil cylinder with feedback regulation, which not only realizes up-down buffering, but also can overcome the defects that the pressure change in a buffering cavity is severe in the up-down buffering process of the conventional forklift lifting oil cylinder, the automatic feedback regulation in the buffering process cannot be realized according to the pressure change in the buffering cavity, and the like.
In order to solve the problems, the invention adopts the technical scheme that: the lifting buffer oil cylinder with the feedback regulation function for the up-down buffer forklift 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, and the end face of the rodless cavity of the piston is provided with a buffer cavity; the center of the other end face of the piston is provided with a through hole, and the same circumference of the end face is provided with a stepped hole. 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 communicated oil way which is communicated with the rod cavity and the rodless cavity all the time, and a buffer sleeve which plays a role in supporting and buffering is arranged in the cylinder cover and close to the rod cavity. According to the invention, 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 in the piston, and at the moment, hydraulic oil in the rodless cavity can only flow out of the buffering gap formed by the buffering plunger and the buffering cavity, so that the buffering 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 at the end of a descending stroke is reduced, and the descending buffering is realized.
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; a buffer cavity is formed in the center of the end face of a rodless cavity of a first stepped shaft of the piston, a through hole is formed in the center of the end face of a second stepped shaft 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, M stepped holes are uniformly formed in the same circumference on the end face of the through hole of the piston, the stepped hole is provided with two steps, the end face side of the second stepped shaft of the piston, which is close to the second stepped shaft of the piston, is the front part of the stepped hole, the diameter of the front part of the stepped hole is large, the diameter of the middle part of the stepped hole is middle, the diameter of the bottom of; the piston is provided with M feedback oil paths, each feedback oil path corresponds to a stepped hole one by one, and each feedback oil path is communicated with the bottom of the corresponding stepped hole. The stepped hole in the piston is not communicated with the through hole and the buffer cavity.
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.
In the above-mentioned buffer cylinder, the feedback oil circuit is characterized in that the feedback oil circuit is composed of a feedback adjusting hole and a radial connecting hole, the feedback adjusting hole is provided on the same circumference of the end face of the rod cavity of the first stepped shaft of the piston, the radial connecting hole is provided on the outer circumferential surface of the first stepped shaft of the piston, and the connecting hole is communicated with the feedback adjusting hole and the bottom of the stepped hole. The feedback oil paths in the piston can be designed to be communicated or mutually independent according to the process requirement.
In the above-mentioned buffer cylinder, the piston shoulder hole in install the spring holder in proper order, the spring, main valve core, axial through hole is seted up to the spring holder to install at the shoulder hole front portion through threaded connection, main valve core installs at the shoulder hole middle part, spring one end compresses tightly the spring holder, and the spring mounting chamber terminal surface of main valve core is compressed tightly to one end in addition, compresses tightly main valve core on the ladder of shoulder hole bottom, through adjusting the spring holder, the precompression volume that the control spring compressed tightly main valve core.
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 rodless cavity, the number and the size of the large radial holes are suitable for ensuring the oil passing capacity of the rod cavity of the oil cylinder, and the communicated oil way consists of the large radial hole, a gap of the concave 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 holes, and the radial holes penetrate through the piston rod concave cavity.
In the buffer oil cylinder, one end of the main valve core is provided with the spring installation cavity, the other end of the main valve core is processed into a conical surface, the center of the inner end surface of the spring installation cavity is provided with the small central hole, the outer circumferential surface of the bottom of the small central hole of the main valve core is provided with the annular damping groove, and the radial small hole penetrating through the annular damping groove and the bottom of the small central hole is formed.
The upper buffer oil way of the buffer oil cylinder consists of N rows of radial small holes at the front end of the cavity of the piston rod, an annular groove and a radial hole on the piston, an annular damping groove, a radial small hole and a central small hole on the main valve core, a stepped hole and a spring seat axial through hole. Under the normal working condition of the oil cylinder, the upper buffer oil way is pressed on the stepped hole by the spring because of the main valve core, the radial hole on the piston is disconnected with the annular damping hole on the main valve core, and the upper buffer oil way is disconnected. When the piston rod assembly moves to the position near a cylinder cover, the upper buffer sleeve seals an outlet of a communicating oil way arranged in a rod cavity, the buffer sleeve and the piston rod assembly form a relatively sealed cavity, the pressure in the rod cavity rises, pressure oil in the rod cavity acts on the end surface of the bottom of a main valve core through a feedback oil way, when the acting force of the pressure oil is greater than the pretightening force of a spring, the main valve core moves, a radial hole in the piston is communicated with an annular damping hole in the main valve core, the upper buffer oil way is opened, when the upper buffer oil way is communicated, the flow area formed by the radial small hole and the annular damping hole is related to the feedback pressure, when the feedback pressure is large, the flow area is large, the damping is small, and the; when the feedback pressure is small, the flow area is small, the damping is large, the pressure in the rod cavity is increased, the feedback pressure automatically adjusts the relative displacement of the upper-shaped damping hole of the main valve core ring and the radial hole of the piston, and therefore automatic feedback adjustment in the upper buffering process is achieved.
Drawings
FIG. 1 is a front view of an oil cylinder according to 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 hydraulic cylinder comprises a cylinder cover 1, a cylinder 2, a piston rod 3, a rod cavity 4, a large radial hole 5, a spring seat 6, a spring 7, a main valve core 8, a small central hole 9, N rows of small radial holes 10, a feedback adjusting hole 11, a radial communicating hole 12, a piston 13, a rodless cavity 14, a cylinder head 15, an oil inlet and outlet 16, a buffer plunger 17, a buffer cavity 18, an annular damping groove 19, a small radial hole 20, an annular groove 21, a radial hole 22, a through hole 23, a stepped hole 24, a cavity bottom gap 25 and a buffer sleeve 26.
Detailed Description
The following description of the embodiments refers to the accompanying drawings.
As shown in fig. 1, the up-down buffer forklift lifting cylinder with feedback regulation in the embodiment includes a cylinder body assembly and a piston rod assembly, wherein the cylinder body assembly includes a cylinder cover 1, a cylinder 2 and a cylinder head 15, and the piston rod assembly includes a piston 13 and a piston rod 3. One end of the piston rod 3 is connected with a piston 13, the other end of the piston rod extends out of the oil cylinder from the cylinder cover 1, the piston 13 divides the inner space of the cylinder body assembly into a rod cavity 4 and a rodless cavity 14, and the end face of the rodless cavity of the piston 13 is provided with a buffer cavity 18; the piston 13 has a through hole 23 formed in the center of the other end surface thereof and a stepped hole 24 formed on the same circumference of the end surface. A cylindrical buffer plunger 17 is connected to the end part of the oil passage at the inlet and the outlet of the cylinder head 15, and an oil inlet and an oil outlet 16 formed on the cylinder head 15 are connected with the rodless cavity 14 through an internal passage of the buffer plunger 17; the piston rod 3 assembly is provided with a communicated oil way which is communicated with the rod cavity 4 and the rodless cavity 14 all the time, and a buffer sleeve 26 which plays a role in supporting and buffering is arranged in the cylinder cover 1 and close to the rod cavity 4. When the piston rod assembly moves to the vicinity of the cylinder head 15, the buffering plunger 17 on the cylinder head is inserted into the buffering cavity 18 in the piston, and hydraulic oil can only flow out from the buffering gap formed by the buffering plunger 17 and the buffering cavity 18, so as to realize lower buffering, and fig. 2 is a schematic flow diagram of hydraulic oil during lower buffering.
As shown in fig. 1, the piston 13 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 a rodless cavity of a first stepped shaft of the piston 13 is provided with a buffer cavity 18, the center of the end face of a second stepped shaft is provided with a through hole 23, the through hole 23 is communicated with the buffer cavity 18, the diameter of the buffer cavity 18 is larger than that of the through hole 23, meanwhile, the same circumference of the end face of the through hole 23 of the piston is uniformly provided with 4 stepped holes 24, each stepped hole 24 is provided with two steps, the end face side of the second stepped shaft close to the piston 13 is the front part of the stepped hole 24, the diameter of the front part of the stepped hole 24 is large, the diameter of the bottom of the stepped hole 24 is small, the outer surface of the second stepped shaft of the piston 13 close to the first; 4 feedback oil paths are formed in the piston 13, each feedback oil path corresponds to one step hole 24, each pair of feedback oil paths are communicated with the bottom of the corresponding step hole 24, the feedback oil paths are not communicated with each other, and the step holes 24 are not communicated with the through holes 23 and the buffer cavity 18.
As shown in FIG. 1, the buffer gap is formed by the outer surface of the buffer plunger 12 and the inner surface of the buffer cavity 13 in the piston, and the buffer requirements under different working conditions can be met by changing the size of the buffer gap and the length of the buffer plunger 12.
As shown in fig. 1, the feedback oil path is composed of a feedback adjusting hole 11 and a radial communicating hole 12, the feedback adjusting hole 11 is formed on the same circumference of the end surface of the rod cavity of the first stepped shaft of the piston 13, and the radial communicating hole 12 is formed on the outer circumferential surface of the first stepped shaft of the piston 13.
As shown in FIG. 1, a spring seat 6, a spring 7 and a main valve element 8 are sequentially arranged in a piston stepped hole 24, the spring seat 6 is provided with an axial through hole and is arranged at the front part of the stepped hole 24 through threaded connection, the main valve element 8 is arranged in the middle of the stepped hole 24, one end of the spring 7 compresses the spring seat 6, the other end compresses the end surface of a spring installation cavity of the main valve element 8, and the main valve element 8 is compressed on a step at the bottom of the stepped hole 24.
As shown in fig. 1, a concave cavity is formed at the end part of the piston rod 3 connected with the second stepped shaft of the piston 13, the concave cavity is sleeved with the second stepped shaft of the piston 13, a large radial hole 5 communicated with the rodless cavity 14 is formed at the bottom of the concave cavity, and the communicated oil path is composed of the large radial hole 5, a gap 25 of the concave cavity at the bottom of the piston rod and a through hole 23; the circumferential surface of the front end of the concave cavity of the piston rod 3 is provided with N rows of radial small holes 10(2 rows of radial small holes, and 4 radial small holes are arranged in each row) which penetrate through the concave cavity.
As shown in FIG. 1, a spring installation cavity is formed in one end of main valve element 8, a conical surface is formed in the other end of main valve element 8, a small central hole 9 is formed in the center of the inner end surface of the spring installation cavity, an annular damping groove 19 is formed in the outer circumferential surface of the bottom of small central hole 9 of main valve element 8, and a small radial hole 20 penetrating through annular damping groove 19 and the bottom of small central hole 9 is formed.
As shown in FIG. 1, the upper buffer oil path is composed of N rows of radial small holes 10 at the front end of the cavity of the piston rod 3, an annular groove 21 and a radial hole 22 on the piston 13, an annular damping groove 19, a radial small hole 20, a central small hole 9, a stepped hole 24 and an axial through hole of the spring seat 6 on the main valve core 8. Under the normal working condition of the oil cylinder, an upper buffer oil path is pressed on a step by a spring 7 because of a main valve core 8, a radial hole 22 on a piston 13 is disconnected with an annular damping groove 19 on the main valve core 8, the upper buffer oil path is disconnected, only when a piston rod assembly moves to the position near a cylinder cover 1, a buffer sleeve 26 and the piston rod assembly form a relatively sealed cavity, the pressure of a rod cavity 4 rises, the pressure of a feedback oil path acting on the bottom end face of the main valve core 8 is larger than the spring force, so that the main valve core 8 moves, the upper buffer oil path is communicated, the upper buffer is realized, and fig. 3 is a schematic flow diagram of hydraulic oil during the.
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.
Claims (7)
1. The up-down buffering forklift lifting oil cylinder with feedback regulation 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, one end of the piston rod is connected with the piston, and the other end of the piston rod extends out of the oil cylinder from the cylinder cover; the center of the end surface of the rodless cavity of the piston is provided with a buffer cavity, the center of the other end surface of the piston is provided with a through hole, and the same circumference of the end surface is provided with a stepped hole; 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 communicated oil way which is communicated with the rod cavity and the rodless cavity all the time, and a buffer sleeve which plays a role in supporting and buffering is arranged in the cylinder cover and close to the rod cavity.
2. The lift cylinder of claim 1, wherein the piston is a stepped shaft, the first stepped shaft having a large diameter and engaging the canister, and the second stepped shaft having a small diameter and engaging the cavity in the piston rod; a buffer cavity is formed in the center of the end face of a rodless cavity of a first stepped shaft of the piston, a through hole is formed in the center of the end face of a second stepped shaft 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, M stepped holes are uniformly formed in the same circumference of the end face of the through hole of the piston, the stepped holes are provided with two steps, the end face side close to the second stepped shaft of the piston is the front part of each stepped hole, the diameter of the front part of each stepped hole is large, the diameter of the bottom of; an annular groove is formed on the outer surface of the second stepped shaft of the piston close to the first stepped shaft, and a radial hole penetrating through the annular groove and the middle part of the stepped hole is formed; the piston is provided with M feedback oil paths, each feedback oil path corresponds to a stepped hole one by one, and each feedback oil path is communicated with the bottom of the corresponding stepped hole.
3. The lift cylinder of claim 2, wherein the feedback oil path is formed by a feedback adjustment hole and a radial connection hole, the feedback adjustment hole is formed on the same circumference of the end surface of the rod cavity of the first step shaft of the piston, the radial connection hole is formed on the outer circumferential surface of the first step shaft of the piston, and the radial connection hole is communicated with the feedback adjustment hole and the bottom of the step hole.
4. A lifting cylinder as claimed in claim 2, wherein the spring seat, the spring and the main valve element are sequentially mounted in the stepped bore of the piston, the spring seat is provided with an axial through hole and is mounted at the front of the stepped bore by means of a screw connection, the main valve element is mounted at the middle of the stepped bore, one end of the spring presses the spring seat, and the other end presses the end face of the spring mounting cavity of the main valve element to press the main valve element against the step at the bottom of the stepped bore.
5. A lifting oil cylinder as claimed in claim 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, 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 of the cavity of the piston rod is provided with N rows of small radial holes, and the small radial holes penetrate through the cavity of the piston rod.
6. A lifting cylinder as claimed in claim 4, wherein the main valve body has a spring mounting cavity formed at one end thereof and a conical surface formed at the other end thereof, the spring mounting cavity has a central aperture formed at a center of an inner end surface thereof, the main valve body has a damping ring formed at a bottom portion thereof and a radial aperture formed at a bottom portion thereof.
7. The lift cylinder of claim 1, wherein the buffer plunger is located within the rodless chamber of the cylinder, and the buffer gap during the lower buffering process is defined by an outer surface of the buffer plunger and an inner surface of the piston buffer chamber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821996481.6U CN209740629U (en) | 2018-11-20 | 2018-11-20 | Up-down buffering forklift lifting oil cylinder with feedback adjustment function |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821996481.6U CN209740629U (en) | 2018-11-20 | 2018-11-20 | Up-down buffering forklift lifting oil cylinder with feedback adjustment function |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209740629U true CN209740629U (en) | 2019-12-06 |
Family
ID=68700272
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201821996481.6U Expired - Fee Related CN209740629U (en) | 2018-11-20 | 2018-11-20 | Up-down buffering forklift lifting oil cylinder with feedback adjustment function |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209740629U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111288040A (en) * | 2020-03-26 | 2020-06-16 | 湖南机电职业技术学院 | Oil cylinder with ultrahigh pressure sealing structure |
-
2018
- 2018-11-20 CN CN201821996481.6U patent/CN209740629U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111288040A (en) * | 2020-03-26 | 2020-06-16 | 湖南机电职业技术学院 | Oil cylinder with ultrahigh pressure sealing structure |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104595281B (en) | Cushion cylinder | |
| US6860370B2 (en) | Controllable damping force hydraulic shock absorber | |
| US8807302B2 (en) | Shock absorber with dual piston | |
| CN201747693U (en) | Hydraulic cylinder with buffer function | |
| US11473645B2 (en) | Hydraulic shock-absorber with hydraulic stop member and adjustment device | |
| CN201747698U (en) | Cushioning device for hydraulic cylinder | |
| US20240093753A1 (en) | Damper with hydraulic compression stop | |
| US20190024814A1 (en) | Check valve for a variable compression internal combustion engine and a connecting rod with the check valve | |
| CN105715612A (en) | Throttling buffer cylinder with integrated buffer cylinder bottom | |
| CN209740629U (en) | Up-down buffering forklift lifting oil cylinder with feedback adjustment function | |
| CN209761913U (en) | Spiral cavity coupling buffer bucket rod oil cylinder | |
| CN103104566B (en) | Plug-in mounting type balance valve | |
| CN110615388A (en) | Up-down buffering forklift lifting oil cylinder with feedback adjustment function | |
| CN109026889B (en) | Buffer overflow valve | |
| CN209493285U (en) | Fork truck buffer lift oil cylinder | |
| CN205533530U (en) | Throttle buffering hydro -cylinder with at bottom of integral type cushioned cylinder | |
| GB2141518A (en) | Elastomeric spring stressed by liquid | |
| CN102654153B (en) | Buffering device for plunger hydraulic cylinder | |
| CN110615387A (en) | Fork truck buffering lifting oil cylinder | |
| CN109058208B (en) | Buffer overflow valve | |
| CN111348594A (en) | Constant-pressure buffering forklift lifting oil cylinder | |
| US10801402B2 (en) | Connecting rod for an internal combustion engine with variable compression | |
| CN101403444B (en) | Non-discharging type liquid-control hydraulic check valve | |
| CN210919637U (en) | Buffer oil cylinder of crusher | |
| CN215058588U (en) | Built-in buffer device of hydraulic actuator cylinder piston |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20191206 Termination date: 20201120 |