Bidirectional buffering hydraulic cylinder with pressure relief cone valve arranged in piston

Abstract

The bidirectional buffering hydraulic cylinder comprises a cylinder barrel, the piston, a piston rod, a guide sleeve, cone valves and valve seats, one or more valve holes for installing the cone valves are formed in the piston, the cone valves and the valve seats are installed in the valve holes, and conical surfaces on the two sides of each cone valve are matched with the conical surfaces of the left valve seat and the right valve seat respectively. The cone valve can move left and right in the valve hole under the action of oil and can make contact with the cone valve on the piston through the cylinder bottom or the guide sleeve and make the cone valve move left or right in the state that the piston rod fully stretches out or fully retracts, the oil passes through the cone valve hole in the piston to communicate a rod cavity with a rodless cavity, stress on the single side of the piston is reduced, and the movement speed of the piston rod is reduced; and the piston is slowly contacted with the guide sleeve or the cylinder bottom, so that the impact is reduced, the buffering effect is achieved, and the hydraulic oil cylinder is protected.

Description

Technical Field

[0001] The invention relates to a bidirectional buffer hydraulic cylinder, in particular to a bidirectional buffer hydraulic cylinder with a built-in pressure relief cone valve in a piston. Background Art

[0002] During the reciprocating operation of the hydraulic cylinder, when the piston rod reaches the end of the stroke, if the running speed is fast, the piston is easy to cause mechanical impact with the guide sleeve or the bottom of the hydraulic cylinder, generating great impact pressure and noise. In order to extend the service life of the hydraulic cylinder sealing system, protect the electroplating layer of the piston rod, the quality of the weld and other structural parts of the main machine from mechanical impact and hydraulic impact, a certain buffer device must be set at the end of its stroke to reduce mechanical impact. The existing technology uses a buffer sleeve assembled in front of the piston to match the inner hole of the guide sleeve, and the large cavity uses a buffer structure in which the buffer plunger matches the plunger hole at the bottom of the cylinder. Due to the influence of the matching accuracy and self-weight of the buffer sleeve and the plunger and the coupling parts, the existing technology is prone to strain during reciprocating motion, resulting in strain on the surface of the buffer component, weakening or loss of the buffer function. At the same time, the existing technology has high buffer pressure, which affects the life of the sealing system. Summary of the invention

[0003] In view of the problems existing in the above-mentioned prior art, the present invention provides a two-way buffer hydraulic cylinder with a built-in pressure relief cone valve on the piston. The hydraulic cylinder mainly consists of a cylinder barrel, a piston rod, and a guide sleeve. The piston is provided with one or more valve holes for installing the cone valve. The cone valve and the valve seat are installed in the valve hole. The cone surfaces on both sides of the cone valve cooperate with the cone surfaces of the left and right valve seats respectively. The cone valve can move left and right in the valve hole under the action of oil, and can contact the cone valve on the piston through the cylinder bottom or the guide sleeve when the piston rod is fully extended or fully retracted. The cone valve moves left or right, and the oil passes through the cone valve hole on the piston to connect the rod cavity and the rodless cavity. The force on one side of the piston is reduced, the movement speed of the piston rod is reduced, the piston slowly contacts with the guide sleeve or the cylinder bottom, the impact is reduced, and a buffering effect is played, which has a protective effect on the hydraulic oil cylinder.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a bidirectional buffer hydraulic cylinder with a built-in pressure relief cone valve in the piston, a cylinder barrel, a piston, a piston rod, a guide sleeve, a cone valve, and a valve seat. The piston rod is slidably arranged in the cylinder barrel through a guide sleeve, and the piston is fixed on the piston rod and arranged between the cylinder barrel and the piston rod. The piston is provided with at least one valve hole for installing the cone valve, and both ends of the cone valve are arranged in the valve hole through the valve seat, so that the cone valve can move left and right in the valve hole under the action of oil, and the valve seat is provided with a cone hole, and the valve hole is blocked by the cone valve and the valve seat.

[0005] Furthermore, it also includes: a clamping key and a fixing bolt, and the piston is fixed to the piston rod by the clamping key and the fixing bolt.

[0006] Furthermore, the latches are two symmetrically arranged semicircular latches.

[0007] Furthermore, the position where the piston rod is installed in the piston is a small head, and its installation position is provided with a protruding step. The piston is mounted on the small head so that one side of the piston is close to the side of the protruding step. The piston rod is provided with a groove for installing a key at the other side where the piston is installed. The key is installed in the groove and connected to the piston by a fixing bolt.

[0008] Furthermore, it also includes: a retaining ring, which is arranged on the left and right sides of the piston and is used to limit the cone valve and the valve seat installed in the piston.

[0009] Furthermore, the cone valve includes: a sealing body and a pressure relief shaft arranged at both ends of the sealing body. The sealing body is slidably arranged in the valve hole. Both ends of the sealing body are provided with conical surfaces. The conical surfaces of the sealing body cooperate with the conical holes of the valve seat to achieve sealing. By moving the cone valve left and right, the conical holes on one of the valve seats are sealed, and the pressure relief shaft can pass through the conical hole of the valve seat and extend out of the left and right end faces of the piston.

[0010] Furthermore, during the extension of the piston rod, the cone valve moves to the right, the cone surface on the right side of the cone valve contacts and fits with the valve seat to seal the oil, the large chamber and the small chamber of the oil cylinder are not connected, and the piston rod extends normally. During the retraction of the piston rod, the cone valve moves to the left, the cone surface on the left side of the cone valve contacts and fits with the valve seat to seal the oil, the large chamber and the small chamber of the oil cylinder are not connected, and the piston rod is retracted normally; when the piston rod is fully extended, when the piston is about to contact the guide sleeve, the pressure relief shaft of the cone valve contacts with the guide sleeve first, the cone valve moves to the left, the cone surface on the right side of the cone valve is out of contact with the valve seat, and the oil passes through the valve hole. The oil in the large and small chambers of the cylinder is connected, the large chamber quickly releases pressure, the small chamber builds up oil pressure, and the piston contacts the guide sleeve slowly to avoid severe mechanical collision; when the cylinder piston rod is fully retracted and the piston is about to contact the bottom of the cylinder barrel, the pressure relief shaft of the cone valve contacts the bottom of the cylinder barrel first, the cone valve moves to the right, the cone surface on the left side of the cone valve and the valve seat are out of contact, the oil passes through the valve hole, the oil in the large and small chambers of the cylinder is connected, the small chamber quickly releases pressure, the large chamber builds up oil pressure, and the piston contacts the bottom of the cylinder barrel slowly to avoid severe mechanical collision.

[0011] The beneficial effects of the present invention are: The piston has a built-in cone valve buffer structure, which eliminates the need to add large and small cavity buffer sleeves, saving internal space in the cylinder. The cone valve moves left and right under the action of oil pressure. The length of the cone valve can be easily adjusted by machining. Increasing or shortening the length of the cone valve pressure relief column can adjust the length of the buffer chamber when the cone valve contacts the guide sleeve or the cylinder bottom. Adding annular grooves and rectangular grooves on the contact end surface of the guide sleeve and the piston can realize rapid start of the cylinder when changing direction, and the cone valve moves left in time to reduce internal leakage, thereby realizing rapid start and retraction of the piston rod; The piston is limited in the groove of the piston rod head by two semicircular clamping keys, and is fixed by screws and screw holes on the piston. The clamping keys are processed with mounting holes and cone valve arc grooves. When the piston moves left and right, the clamping keys are subjected to shear force and the piston rod head is subjected to extrusion force, and the structural reliability is high; One or more sets of cone valves and valve seat assemblies are installed on the piston. Increasing the number of cone valves and valve seat assemblies can increase the amount of oil flowing in the piston and adjust the buffering effect at the end of the stroke. At the same time, one or more rectangular oil grooves are processed on the valve seat to achieve rapid oil flow and adjust the buffering effect; The cone valve and valve seat are installed in the piston, and the two sides are limited by annular baffles, which is convenient for installation and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a schematic diagram of the cross-sectional structure of the present invention; Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure of the cylinder without AA in the middle; Figure 4 for Figure 3 The partially enlarged structural diagram of middle Ⅰ; Figure 5 for Figure 2 Schematic diagram of the partial enlarged structure of middle Ⅱ; Figure 6 It is a schematic diagram of the piston end surface structure; Figure 7 for Figure 6 BB cross-sectional structure diagram; Figure 8 It is a schematic diagram of the valve seat structure: main, left, right and cutaway; Fig. 9 It is a schematic diagram of the cone valve structure; Fig.10 It is a schematic diagram of the key structure; Fig.11 This is a schematic diagram of the side structure of the guide sleeve; Fig.12 for Fig.11 Schematic diagram of the cross-section structure; Fig.13 for Fig.12 Schematic diagram of the structure from the B-direction viewing angle; Fig.14 for Fig.12 Schematic diagram of the structure from the C-direction viewing angle; In the figure: 1. cylinder; 2. piston; 3. piston rod; 4. guide sleeve; 41. annular groove; 42. rectangular groove; 5. cone valve; 51. sealing body; 52. pressure relief shaft; 6. valve seat; 7. valve hole; 8. key; 7. fixing bolt; 8. groove; 9. step; 10. retaining ring. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention is further described in detail below through the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0014] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0015] like Figure 1-14 As shown, a bidirectional buffer hydraulic cylinder with a built-in pressure relief cone valve in the piston comprises a cylinder barrel 1, a piston 2, a piston rod 3, a guide sleeve 4, a cone valve 5, and a valve seat 6. The piston rod 3 is slidably arranged in the cylinder barrel 1 through the guide sleeve 4. The piston 2 is fixed on the piston rod 3 and is arranged between the cylinder barrel 1 and the piston rod 3. One or more groups of valve holes 7 for installing the cone valve 5 are provided on the piston 2. Both ends of the cone valve 5 are arranged in the valve hole 7 through the valve seat 6, so that the cone valve 5 can move left and right in the valve hole 7 under the action of oil. The valve seat 6 is provided with a cone hole, and the valve hole 7 is blocked by the cone valve 5 and the valve seat 6.

[0016] like Figure 2-3 As shown, the bidirectional buffer hydraulic cylinder with a built-in pressure relief cone valve in the piston also includes: a key 8 and a fixing bolt 7. The piston 2 is fixed to the piston rod 3 by the key 8 and the fixing bolt 7. When the piston 2 moves left and right, the key 8 is subjected to shear force, which can avoid the problem that the threaded tightening structure of the piston 2 is easy to loosen under high-frequency vibration, and the structural reliability is high.

[0017] like Figure 3 , 10 As shown, the latching keys 8 are two symmetrically arranged semicircular latching keys 8 .

[0018] like Figure 2 , 5 As shown, the position where the piston rod 3 is installed with the piston 2 is a small head, and its installation position is provided with a protruding step 9. The piston 2 is mounted on the small head so that one side of the piston 2 is close to the side of the protruding step 9. The piston rod 3 is provided with a groove 8 for installing a key 8 at the other side where the piston 2 is installed. The key 8 is installed in the groove 8 and is connected to the piston 2 by a fixing bolt 7.

[0019] like Figure 2 , 5 As shown, the bidirectional buffer hydraulic cylinder with a built-in pressure relief cone valve in the piston also includes: a retaining ring 10, which is arranged on the left and right sides of the piston 2 and is used to limit the cone valve 5 and the valve seat 6 installed in the piston 2. The left side of the piston 2 is processed with a fixing screw hole for the card key 8, and the right side is processed with a mounting groove for the retaining ring 10.

[0020] like Fig. 9 As shown, the cone valve 5 includes: a sealing body 51 and a pressure relief shaft 52 arranged at both ends of the sealing body 51. The sealing body 51 is slidably set in the valve hole 7. Both ends of the sealing body 51 are provided with conical surfaces. The conical surface of the sealing body 51 cooperates with the conical hole of the valve seat 6 to achieve sealing. By moving the cone valve 5 left and right, the conical hole on one of the valve seats 6 is sealed, and the pressure relief shaft 52 can pass through the conical hole of the valve seat 6 and extend out of the left and right end faces of the piston 2.

[0021] The maximum radius of the retaining ring 10 cannot affect the tapered hole of the pressure relief shaft 52 passing through the valve seat 6, and at least it can play a role in limiting the valve seat 6. In order to improve the fixing strength, a notch can be set at the retaining ring 10 where the valve seat 6 is limited to increase the shielding area and improve the fixing strength.

[0022] like Figure 3 As shown, the corresponding cone valve 5 and valve seat 6 are installed according to the valve hole 7 on the piston 2. By increasing the number of valve holes 7, cone valves 5 and valve seats 6, the amount of oil flowing in the piston 2 can be increased and the buffering effect at the end of the stroke can be adjusted.

[0023] like Figure 8 As shown, one or more rectangular oil-passing grooves are processed on the valve seat 6 to achieve rapid oil passing and adjust the buffering effect.

[0024] like Fig. 9 As shown, increasing or shortening the length of the pressure relief shaft 52 of the cone valve 5 can adjust the length of the buffer chamber when the pressure relief shaft 52 contacts the guide sleeve 4 or the cylinder bottom, adjust the oil volume of the buffer chamber, and adjust the buffer time and effect.

[0025] like Figure 11-14 As shown, the addition of an annular groove 41 and a rectangular groove 42 on the contact end surface of the guide sleeve 4 and the piston 2 can realize rapid start-up of the oil cylinder when switching, and the cone valve 5 moves left in time to reduce internal leakage, thereby realizing rapid start-up and retraction of the piston rod 3.

[0026] During the extension of the piston rod 3, the cone valve 5 moves to the right, the cone surface on the right side of the cone valve 5 and the valve seat 6 are in contact with each other to seal the oil, the large chamber and the small chamber of the oil cylinder are not in series, and the piston rod 3 is normally extended. During the retraction of the piston rod 3, the cone valve 5 moves to the left, the cone surface on the left side of the cone valve 5 and the valve seat 6 are in contact with each other to seal the oil, the large chamber and the small chamber of the oil cylinder are not in series, and the piston rod 3 is normally retracted; when the piston rod 3 is fully extended, when the piston 2 is about to contact the guide sleeve 4, the pressure relief shaft 52 of the cone valve 5 contacts the guide sleeve 4 first, the cone valve 5 moves to the left, the cone surface on the right side of the cone valve 5 and the valve seat 6 are out of contact, and the oil passes through the valve hole 7 , the oil in the large and small chambers of the cylinder are connected, the large chamber quickly releases pressure, the small chamber builds up oil pressure, and the piston 2 slowly contacts the guide sleeve 4 to avoid severe mechanical collision; when the cylinder piston rod 3 is fully retracted, the piston 2 is about to contact the bottom of the cylinder barrel 1, the pressure relief shaft 52 of the cone valve 5 first contacts the bottom of the cylinder barrel 1, the cone valve 5 moves to the right, the cone surface on the left side of the cone valve 5 and the valve seat 6 are out of contact, and the oil passes through the valve hole 7, the oil in the large and small chambers of the cylinder are connected, the small chamber quickly releases pressure, the large chamber builds up oil pressure, and the piston 2 slowly contacts the bottom of the cylinder barrel 1 to avoid severe mechanical collision.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A bidirectional buffer hydraulic cylinder with a built-in pressure relief cone valve in the piston, characterized in that: Cylinder, piston, piston rod, guide sleeve, cone valve, valve seat, the piston rod is slidably arranged in the cylinder through the guide sleeve, the piston is fixed on the piston rod and arranged between the cylinder and the piston rod, the piston is provided with at least one valve hole for installing the cone valve, both ends of the cone valve are arranged in the valve hole through the valve seat, so that the cone valve can move left and right in the valve hole under the action of oil, the valve seat is provided with a cone hole, and the valve hole is blocked by the cone valve and the valve seat.

2. A bidirectional buffer hydraulic cylinder with a piston having a built-in pressure relief cone valve according to claim 1, characterized in that: Also includes: A clamping key and a fixing bolt, wherein the piston is fixed on the piston rod by means of the clamping key and the fixing bolt.

3. A bidirectional buffer hydraulic cylinder with a piston and a built-in pressure relief cone valve according to claim 2, characterized in that: The latching keys are two symmetrically arranged semicircular latching keys.

4. A bidirectional buffer hydraulic cylinder with a piston having a built-in pressure relief cone valve according to claim 2, characterized in that: The position where the piston rod is installed with the piston is a small head, and its installation position is provided with a protruding step. The piston is mounted on the small head so that one side of the piston is close to the side of the protruding step. The piston rod is provided with a groove for installing a key at the other side where the piston is installed. The key is installed in the groove and connected to the piston by a fixing bolt.

5. A bidirectional buffer hydraulic cylinder with a piston having a built-in pressure relief cone valve according to claim 4, characterized in that: Also includes: The retaining ring is arranged on the left and right sides of the piston and is used to limit the cone valve and the valve seat installed in the piston.

6. A bidirectional buffer hydraulic cylinder with a piston having a built-in pressure relief cone valve according to claim 4, characterized in that: The cone valve includes: a sealing body and a pressure relief shaft arranged at both ends of the sealing body. The sealing body is slidably arranged in the valve hole. Both ends of the sealing body are provided with conical surfaces. The conical surfaces of the sealing body cooperate with the conical holes of the valve seat to achieve sealing. By moving the cone valve left and right, the conical hole on one of the valve seats is sealed, and the pressure relief shaft can pass through the conical hole of the valve seat and extend out of the left and right end faces of the piston.

7. A bidirectional buffer hydraulic cylinder with a piston having a built-in pressure relief cone valve according to claim 6, characterized in that: During the extension of the piston rod, the cone valve moves to the right, the cone surface on the right side of the cone valve contacts and fits with the valve seat to seal the oil, the large chamber and the small chamber of the oil cylinder are not connected, and the piston rod extends normally. During the retraction of the piston rod, the cone valve moves to the left, the cone surface on the left side of the cone valve contacts and fits with the valve seat to seal the oil, the large chamber and the small chamber of the oil cylinder are not connected, and the piston rod is retracted normally. When the piston rod is fully extended and the piston is about to contact the guide sleeve, the pressure relief shaft of the cone valve contacts the guide sleeve first, the cone valve moves to the left, the cone surface on the right side of the cone valve disengages from the valve seat, the oil passes through the valve hole, the large and small chambers of the cylinder are connected, the large chamber quickly releases pressure, the small chamber builds up oil pressure, and the piston contacts the guide sleeve slowly to avoid severe mechanical collision; when the cylinder piston rod is fully retracted and the piston is about to contact the bottom of the cylinder barrel, the pressure relief shaft of the cone valve contacts the bottom of the cylinder barrel first, the cone valve moves to the right, the cone surface on the left side of the cone valve disengages from the valve seat, the oil passes through the valve hole, the large and small chambers of the cylinder are connected, the small chamber quickly releases pressure, the large chamber builds up oil pressure, and the piston contacts the bottom of the cylinder barrel slowly to avoid severe mechanical collision.

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