Oil cylinder type clamping device

Abstract

The utility model discloses an oil cylinder type clamping device which comprises an oil cylinder main body with a first cavity and a second cavity which are not communicated with each other, a first piston part which divides the first cavity into a first oil cavity with a first oil port and a second oil cavity with a second oil port, one end of the first piston part is connected with a first piston rod with a hollow cavity, and the other end of the first piston part is connected with a second piston rod with a second oil port. One end of the first piston rod is arranged to hermetically penetrate out of the end part of the oil cylinder main body to reciprocate; the second piston part divides the second cavity into a third oil cavity with a third oil port and a fourth oil cavity with a fourth oil port, the second piston part is connected with a second piston rod, and the second piston rod is arranged to penetrate through the first piston part in a sealed mode to do reciprocating motion along the hollow cavity; the clamping mechanism comprises two clamping arms, the middles of the two clamping arms are rotationally connected to one end of the first piston rod, and the tails of the two clamping arms are rotationally connected to one end of the second piston rod. The problems that a traditional clamping device is not compact enough in structure and large in installation space are solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to oil cylinder clamping technical field, especially a kind of oil cylinder type clamping device. BACKGROUND

[0002] At present, clamping mechanism is often used in working machine, clamping mechanism can imitate the function of some actions of human hand and arm, realize the automatic operation device of fixed program grasping, carrying object or operating tool, existing clamping processing can be divided into parallel jaw, three-point jaw, rotary jaw, swing jaw and other performance forms.The driving form of current clamping mechanism has multiple, wherein the most common is to adopt several ways of oil cylinder driving.Mode one, adopt a single oil cylinder drive;Mode two, adopt two single oil cylinders, each drive a telescopic arm, oil port is connected in parallel;The defect of method one is that telescopic mechanism telescopic length is short, and support strength is not enough;The defect of method two is that two single oil cylinders need to be connected with oil pipe respectively, and at least one oil pipe of one of the oil cylinders will move back and forth with the movable arm, so that friction occurs between the oil pipe and the telescopic arm, resulting in oil pipe damage, which makes hydraulic pipeline arrangement very difficult. SUMMARY

[0003] In view of the defects existing in the prior art, the utility model provides an oil cylinder type clamping device, which has the functions of telescoping and clamping, higher integration, smaller installation space and more compact structure.

[0004] The utility model adopts the following technical scheme:

[0005] An oil cylinder type clamping device comprises:

[0006] An oil cylinder body is provided with a first cavity and a second cavity which are not connected to each other;

[0007] A first piston part can reciprocate in the first cavity and separate the first cavity into a first oil chamber and a second oil chamber, the first oil chamber is provided with a first oil port, and the second oil chamber is provided with a second oil port, one end of the first piston part towards the first oil chamber is connected with a first piston rod with a hollow cavity, the end of the first piston rod away from the first piston part extends out of the end of the oil cylinder body, the outer edge of the first piston rod is sealingly connected with the end of the oil cylinder body, and the first piston rod is arranged to reciprocate out of the end of the oil cylinder body;

[0008] a second piston part reciprocally movable in the second cavity and separating the second cavity into a third oil cavity and a fourth oil cavity, the third oil cavity being provided with a third oil port, the fourth oil cavity being provided with a fourth oil port, one end of the second piston part facing the third oil cavity being connected with a second piston rod, the second piston rod extending out of the end of the oil cylinder body from the hollow cavity of the first piston rod after penetrating the second cavity, the outer edge of the second piston rod sealingly engaging the first piston part, and the second piston rod being arranged to reciprocate in the hollow cavity after penetrating the first piston part;

[0009] a clamping mechanism including two clamping arms arranged to be openable and closable, middle parts of the two clamping arms being rotatably connected to the end of the first piston rod away from the first piston part, tail parts of the two clamping arms being rotatably connected to the end of the second piston rod away from the second piston part through a linkage structure.

[0010] Further, the radius of the first piston rod is R1, and the outer radius of the second piston rod is R2, R2 = √2R1.

[0011] Further, the first oil port, the second oil port, the third oil port and the fourth oil port are arranged at the same side position of the oil cylinder body.

[0012] Further, the linkage structure includes two linkages, the middle parts of the two clamping arms are respectively provided with first hinged joints, the tail parts of the two clamping arms are respectively provided with second hinged joints, and the driving end of the second piston rod is provided with a third hinged joint, the two first hinged joints are respectively hinged to the two driving ends of the first piston rod, and the two linkages are respectively hinged to the third hinged joint on the driving end of the second piston rod away from the second hinged joints.

[0013] Further, the oil cylinder body is provided with an oil cylinder hole through which the first piston rod extends out of the end of the oil cylinder body, and the oil cylinder hole is provided with a first sealing member, the inner edge of the first sealing member sealingly engaging the first piston rod, and the first piston rod is arranged to reciprocate after penetrating the first sealing member.

[0014] Further, the first piston part is provided with a piston hole through which the second piston rod extends into the hollow cavity, and the piston hole is provided with a second sealing member, the inner edge of the second sealing member sealingly engaging the second piston rod, and the second piston rod is arranged to reciprocate after penetrating the second sealing member.

[0015] Further, the oil cylinder body is internally provided with a separation part, the separation part separates the oil cylinder body into a first cavity and a second cavity, the separation part is provided with a separation hole through which an end of the second piston rod away from the second piston part extends to the second oil cavity, the separation hole is internally provided with a third sealing element, an inner edge of the third sealing element sealingly engages the second piston rod, and the second piston rod is arranged to pass through the third sealing element to reciprocate.

[0016] Further, the two clamping arms are of the same size and shape and are symmetrically arranged relative to the second piston rod, and the heads of the two clamping arms are provided with clamping parts for clamping workpieces.

[0017] Further, the oil cylinder type clamping device further comprises an oil path control system for controlling the extension and retraction of the first piston rod and the second piston rod, the oil path control system comprises an oil supply device, an oil pump and a three-position four-way valve, an input end of the oil pump is connected with the oil supply device, an output end of the oil pump is in communication with a P oil port of the three-position four-way valve, a T oil port of the three-position four-way valve is in communication with the oil supply device, A oil ports of the three-position four-way valve are respectively in communication with the second oil port and a fourth oil port, and B oil ports of the three-position four-way valve are respectively in communication with the first oil port and a third oil port.

[0018] Further, the oil path control system further comprises a two-position three-way valve A, a two-position three-way valve B, a two-position two-way valve, a relief valve A and a relief valve B, input ends of the two-position three-way valve A and the two-position three-way valve B are in communication with the B oil port of the three-position four-way valve, an output end of the two-position three-way valve A is in communication with the third oil port, an output end of the two-position three-way valve B is in communication with the first oil port, an input end of the two-position two-way valve is in communication with the A oil port of the three-position four-way valve, an output end of the two-position two-way valve is in communication with the second oil port, an output end of the relief valve A is in communication with an oil port of the two-position three-way valve A, an input end of the relief valve A is in communication with the third oil port, an output end of the relief valve B is in communication with an oil port of the two-position three-way valve B, and an input end of the relief valve B is in communication with the first oil port.

[0019] Compared with the prior art, the oil cylinder type clamping device has at least the following beneficial effects:

[0020] The two piston rods are integrally arranged in the oil cylinder body and are connected in a nested manner, and the extension and retraction of the two piston rods do not interfere with each other, so that the device has a compact layout and requires a small installation space; the clamping and position movement of the clamping mechanism are jointly controlled by the extension and retraction of the first piston rod and the second piston rod, so that the device has both clamping and moving functions, and compared with the prior art in which two groups of oil cylinders are required to realize clamping action, the oil cylinder type clamping device has higher integration, requires smaller installation space, has a more compact layout, and has both clamping and moving functions, and is more practical.BRIEF DESCRIPTION OF DRAWINGS BRIEF DESCRIPTION OF DRAWINGS

[0021] Fig. 1 is a simple schematic diagram of the oil cylinder type clamping device of the embodiment of the utility model;

[0022] Fig. 2 is a connection schematic diagram of the clamping mechanism and the first piston rod and the second piston rod of the embodiment of the utility model;

[0023] Fig. 3 is a schematic diagram of the connection of the oil circuit control system and each oil port of the oil cylinder main body of the embodiment of the utility model;

[0024] In the drawing: 1, oil cylinder main body; 11, isolation part; 12, first oil cavity; 13, second oil cavity; 14, third oil cavity; 15, fourth oil cavity; 16, first oil port; 17, second oil port; 18, third oil port; 19, fourth oil port; 2, first piston part; 21, first piston rod; 3, second piston part; 31, second piston rod; 4, clamping mechanism; 41, clamping arm; 42, first hinged fulcrum; 43, second hinged fulcrum; 44, connecting rod; 45, third hinged fulcrum; 46, clamping part; 5, oil circuit control system; 51, oil supply equipment; 52, oil pump; 53, three-position four-way valve; 54, two-position three-way valve A; 55, two-position three-way valve B; 56, two-position two-way valve; 57, overflow valve A; 58, overflow valve B. DETAILED DESCRIPTION

[0025] Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments, however, can be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and fully convey the inventive concept of example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the several views of the drawings, and description thereof is omitted.

[0026] The words expressing position and direction described in the utility model are all explained by taking the drawings as examples, but changes can also be made according to needs, and the changes made are all included in the protection scope of the utility model.

[0027] As Figs. 1 to 3 shown, an oil cylinder type clamping device provided by the utility model comprises:

[0028] The oil cylinder main body 1 is internally provided with a first cavity and a second cavity which are not communicated with each other;

[0029] A first piston part 2 reciprocally moves in the first cavity and separates the first cavity into a first oil cavity 12 and a second oil cavity 13, the first oil cavity 12 is provided with a first oil port 16, the second oil cavity 13 is provided with a second oil port 17, one end of the first piston part 2 towards the first oil cavity 12 is connected with a first piston rod 21 with a hollow cavity, the other end of the first piston rod 21 extends out of the end of the oil cylinder body 1, the outer edge of the first piston rod 21 sealingly engages the end of the oil cylinder body 1, the first piston rod 21 is arranged to reciprocally move through the end of the oil cylinder body 1;

[0030] A second piston part 3 reciprocally moves in the second cavity and separates the second cavity into a third oil cavity 14 and a fourth oil cavity 15, the third oil cavity 14 is provided with a third oil port 18, the fourth oil cavity 15 is provided with a fourth oil port 19, one end of the second piston part 3 towards the third oil cavity 14 is connected with a second piston rod 31, the other end of the second piston rod 31 extends out of the end of the oil cylinder body 1 from the hollow cavity of the first piston rod 21 after sealingly penetrating out of the second cavity, the outer edge of the second piston rod 31 sealingly engages the first piston part 2, and the second piston rod 31 is arranged to reciprocally move in the hollow cavity after penetrating through the first piston part 2;

[0031] A clamping mechanism 4 includes two clamping arms 41 arranged to be opened and closed, the middle parts of the two clamping arms 41 are respectively rotatably connected to the end of the first piston rod 21 away from the first piston part 2, the tail parts of the two clamping arms 41 are rotatably connected to the end of the second piston rod 31 away from the second piston part 3 through a linkage structure.

[0032] In this embodiment, the first piston part 2 and the second piston part 3 are respectively slidingly arranged in the first cavity and the second cavity of the oil cylinder body 1, the first cavity and the second cavity are sealed from each other, so that the hydraulic oil does not flow to each other, the first piston rod 21 has a hollow cavity for nesting connection of the second piston rod 31, the second piston rod 31 can reciprocally move in the hollow cavity of the first piston rod 21, the first oil cavity 12 and the second oil cavity 13 are supplied with oil from the first oil port 16 and the second oil port 17 to control the extension and retraction of the first piston rod 21, the third oil cavity 14 and the fourth oil cavity 15 are supplied with oil from the third oil port 18 and the fourth oil port 19 to control the extension and retraction of the second piston rod 31, so that the clamping and position moving of the clamping mechanism 4 are jointly controlled by the extension and retraction of the first piston rod 21 and the second piston rod 31.

[0033] The working principle of the clamping mechanism 4 controlled by the first piston rod 21 and the second piston rod 31 is as follows: when the first piston rod 21 is stationary and the second piston rod 31 is retracted, the second piston rod 31 drives the tail portions of the two clamping arms 41 to approach each other, and simultaneously drives the middle portions of the two clamping arms 41 to rotate towards each other with the end portion of the first piston rod 21 away from the first piston portion 2 as a rotating support point, and then the clamping ends of the two clamping arms 41 approach each other, so that the clamping action of the clamping mechanism 4 is realized; when the first piston rod 21 is stationary and the second piston rod 31 is extended, the second piston rod 31 drives the tail portions of the two clamping arms 41 to move away from each other, and simultaneously drives the middle portions of the two clamping arms 41 to rotate in opposite directions with the end portion of the first piston rod 21 away from the first piston portion 2 as a rotating support point, and then the clamping ends of the two clamping arms 41 move away from each other, so that the releasing action of the clamping mechanism 4 is realized; when the first piston rod 21 and the second piston rod 31 move simultaneously while the clamping mechanism 4 remains in the clamping state, the position movement of the clamping mechanism 4 is realized.

[0034] The utility model discloses an integrated two piston rods in the oil cylinder main part 1, and the two piston rods adopt the nesting connection mode, and the telescopic action of the two piston rods does not interfere with each other, makes the device compact layout, and the installation space is small, simultaneously, the clamping and position movement of the clamping mechanism 4 are controlled by the telescopic of the first piston rod 21 and the second piston rod 31, so that the device has two functions of clamping and moving, compared with the need using two groups of oil cylinders to realize the clamping action, the integrated oil cylinder clamping device of the utility model has higher integration, and the required installation space is smaller, and the layout is more compact, and also has two functions of clamping and moving, and the practicality is higher.

[0035] As a preferred embodiment, the radius of the first piston rod 21 is R1, and the outer radius of the second piston rod 31 is

[0036] In the embodiment, in order to ensure that the first piston rod 21 and the second piston rod 31 can move simultaneously, and then keep the clamping state of the clamping mechanism 4 stable, the size between the piston and the piston rod has certain requirements: assuming that the radius of the first piston rod 21 is R1, which is the same as the inner radius of the second piston rod 31, and the outer radius of the second piston rod 31 is R2; the radius of the first piston portion 2 is R3, and the radius of the second piston portion 3 is R4; first, the first piston rod 21 and the second piston rod 31 are simultaneously extended, and then the area of the hydraulic oil contact of the first piston portion 2, the second piston portion 3, the second oil cavity 13 and the fourth oil cavity 15 needs to be the same, that is, πR4 2 = πR3 2 - πR1 2 Therefore, the inner diameter of the second piston portion 3 and the mounting cylinder needs to be reduced during design, so as to meet the above size relationship.

[0037] Secondly, the first piston rod 21 and the second piston rod 31 are retracted simultaneously, and under the condition of meeting the above size condition, the areas of the first piston 2 and the second piston 3 in contact with the hydraulic oil in the first oil chamber 12 and the third oil chamber 14 are the same, πR3 2 -πR2 2 =πR4 2 -πR1 2 , the size relationship formula is substituted, then πR3 2 -πR2 2 =πR3 2 -2πR1 2 , the formula is simplified to obtain That is, the size of the second piston rod 31 and the first piston rod 21 needs to meet the relationship of

[0038] As a preferred embodiment, the first oil port 16, the second oil port 17, the third oil port 18 and the fourth oil port 19 are arranged at the same side of the oil cylinder body 1. In this way, the oil circuit layout is more simple.

[0039] As a preferred embodiment, the connecting rod structure includes two connecting rods 44, the middle parts of the two clamping arms 41 are respectively provided with first hinged joints 42, the tail parts of the two clamping arms 41 are respectively provided with second hinged joints 43, the driving end of the second piston rod 31 is provided with a third hinged joint 45, the two first hinged joints 42 are respectively hinged to the two driving ends of the first piston rod 21, and the ends of the two connecting rods 44 away from the second hinged joints 43 are hinged to the third hinged joint 45 on the driving end of the second piston rod 31.

[0040] In the embodiment, the two clamping arms 41 can rotate around the first hinged joints 42, the second hinged joints 43 at the tail parts of the two clamping arms 41 are hinged to one end of the connecting rod 44, the hinged part can rotate with each other, the other end of the two connecting rods 44 are connected to the end face of the second piston rod 31 for hinging, and the hinged part can freely rotate; the transmission connection between the clamping arm 41 and the second piston rod 31 is realized through the connecting rod 44, the transmission precision is good, and the clamping is more flexible.

[0041] As a preferred embodiment, the oil cylinder body 1 is provided with an oil cylinder hole through which the first piston rod 21 extends out of the end part of the oil cylinder body 1, and a first sealing member is arranged in the oil cylinder hole. The inner edge of the first sealing member sealingly engages the first piston rod 21, and the first piston rod 21 is arranged to pass through the first sealing member for reciprocating movement. By arranging the first sealing member, the sealing performance between the first piston rod 21 and the oil cylinder body 1 is improved. At the same time, the first sealing member has the advantages of low cost, easy installation and replacement, and still can provide excellent protection against dust entering.

[0042] ​As a preferred embodiment, the first piston part 2 is provided with a piston hole through which the second piston rod 31 extends to the hollow cavity, and a second sealing member is arranged in the piston hole to sealingly engage the inner side of the second piston rod 31, and the second piston rod 31 is arranged to reciprocate through the second sealing member.

[0043] In this embodiment, the second sealing member is arranged on the first piston part 2 to improve the sealing performance between the second piston rod 31 and the first piston part 2, and the second sealing member has low cost, is easy to install and replace, and still provides excellent advantages of preventing hydraulic oil from entering the hollow cavity.

[0044] As a preferred embodiment, the oil cylinder body 1 is internally provided with a partition part 11 that separates the inside of the oil cylinder body 1 into a first cavity and a second cavity, the partition part 11 is provided with a partition hole through which the second piston rod 31 extends to the second oil cavity 13 away from the second piston part 3, and a third sealing member is arranged in the partition hole to sealingly engage the inner side of the second piston rod 31, and the second piston rod 31 is arranged to reciprocate through the third sealing member.

[0045] In this embodiment, the first cavity and the second cavity are not communicated with each other by the partition part 11, and the third sealing member is arranged in the partition hole of the partition part 11 to improve the sealing performance between the second piston rod 31 and the partition part 11, and the third sealing member has low cost, is easy to install and replace, and still provides excellent advantages of preventing hydraulic oil in the two oil cavities from penetrating each other.

[0046] As a preferred embodiment, the two clamping arms 41 are the same in size and shape and are symmetrically arranged with respect to the second piston rod 31, and the first ends of the two clamping arms 41 are provided with clamping parts 46 for clamping workpieces.

[0047] In this embodiment, the two clamping arms 41 are the same in size and shape, which facilitates production and processing and reduces manufacturing cost; and the clamping parts 46 are arranged to increase the clamping area and ensure that the clamping mechanism 4 stably clamps workpieces.

[0048] As a preferred embodiment, an oil circuit control system 5 for controlling the extension and retraction of the first piston rod 21 and the second piston rod 31 is further included, the oil circuit control system 5 includes an oil supply device 51, an oil pump 52, and a three-position four-way valve 53, the input end of the oil pump 52 is connected with the oil supply device 51, the output end of the oil pump 52 is in communication with the P oil port of the three-position four-way valve 53, the T oil port of the three-position four-way valve 53 is in communication with the oil supply device 51, the A oil port of the three-position four-way valve 53 is in communication with the second oil port 17 and the fourth oil port 19, respectively, and the B oil port of the three-position four-way valve 53 is in communication with the first oil port 16 and the third oil port 18, respectively.

[0049] In order to accurately control the precise movement of the first piston rod 21 and the second piston rod 31 to achieve the precise clamping and position movement of the clamping mechanism 4, a set of oil circuit control systems 5 is provided in the embodiment, which accurately controls the oil inlet and oil return of each oil port through the oil circuit control system 5 to realize the extension and retraction of the first piston rod 21 and the second piston rod 31. The control principle of the oil circuit control system 5 of the embodiment is as follows:

[0050] When the clamping mechanism 4 does not clamp any object, the extension and retraction actions of the first piston rod 21 and the second piston rod 31 are mainly controlled by the three-position four-way valve 53. When the three-position four-way valve 53 is pushed to the right position, the oil pump 52 supplies oil to the second oil chamber 13 and the fourth oil chamber 15, and the first oil chamber 12 and the third oil chamber 14 return oil to the oil supply device 51, so as to realize the simultaneous extension of the first piston rod 21 and the second piston rod 31. When the three-position four-way valve 53 is pushed to the left position, the oil pump 52 supplies oil to the first oil chamber 12 and the third oil chamber 14, and the second oil chamber 13 and the fourth oil chamber 15 return oil to the oil supply device 51, so as to realize the simultaneous retraction of the first piston rod 21 and the second piston rod 31. When the three-position four-way valve 53 is pushed to the middle position, the positions of the first piston rod 21 and the second piston rod 31 are maintained.

[0051] As a preferred embodiment, the oil circuit control system 5 further comprises a two-position three-way valve A 54, a two-position three-way valve B 55, a two-position two-way valve 56, an overflow valve A 57, and an overflow valve B 58. The input end of the two-position three-way valve A 54 and the input end of the two-position three-way valve B 55 are in communication with the B oil port of the three-position four-way valve 53. The output end of the two-position three-way valve A 54 is in communication with the third oil port 18. The output end of the two-position three-way valve B 55 is in communication with the first oil port 16. The input end of the two-position two-way valve 56 is in communication with the A oil port of the three-position four-way valve 53. The output end of the two-position two-way valve 56 is in communication with the second oil port 17. The output end of the overflow valve A 57 is in communication with the oil port of the two-position three-way valve A 54. The input end of the overflow valve A 57 is in communication with the third oil port 18. The output end of the overflow valve B 58 is in communication with the oil port of the two-position three-way valve B 55. The input end of the overflow valve B 58 is in communication with the first oil port 16.

[0052] In order to realize the stable clamping state of the clamping mechanism 4, the extension of the first piston rod 21 and the second piston rod 31 needs to be controlled. Among them,

[0053] The extension principle of the piston rod when the clamping mechanism 4 is in the basic state: switch the three-position four-way valve 53 to the right position, at which time the second oil chamber 13 and the fourth oil chamber 15 are filled with oil, and the first oil chamber 12 and the third oil chamber 14 are returned to oil. However, to ensure the clamping effect, the third oil chamber 14 needs to have a certain pressure in the oil return state to ensure that the pressure is greater than that of the first oil chamber 12. At this time, the two-position three-way valve A 54 is switched to the left position, and the two-position two-way valve 56 and the two-position three-way valve B 55 remain in place. At this time, the oil return line of the third oil chamber 14 needs to pass through an overflow valve A 57, and at the same time, the first oil chamber 12 returns to oil freely. When the second oil chamber 13 and the fourth oil chamber 15 continue to be filled with oil, due to the action of the front clamping mechanism 4, the second piston rod 31 has a tendency to move forward relative to the first piston rod 21, but due to the presence of the clamped object, the clamping mechanism 4 is hindered and cannot continue to extend, thereby enabling the clamping mechanism 4 to maintain the state of continued clamping. Until the oil line pressure of the third oil chamber 14 gradually rises to the opening pressure of the overflow valve A 57, the overflow valve A 57 is turned on to return the oil line, and the first piston rod 21 and the second piston rod 31 can extend forward while the clamping mechanism 4 remains clamped.

[0054] The retraction principle of the piston rod when the clamping mechanism 4 is in the clamped state: switch the three-position four-way valve 53 to the left position, at which time the first oil chamber 12 and the third oil chamber 14 are filled with oil, and the second oil chamber 13 and the fourth oil chamber 15 are returned to oil. However, to ensure the clamping effect, the third oil chamber 14 needs to have a pressure greater than that of the first oil chamber 12 in the oil filling state. At this time, the two-position three-way valve B 55 is switched to the left position, and the two-position two-way valve 56 and the two-position three-way valve A 54 remain in place. At this time, the oil inlet line of the first oil chamber 12 needs to pass through an overflow valve B 58, and at the same time, the third oil chamber 14 freely fills with oil. When the first oil chamber 12 and the third oil chamber 14 continue to be filled with oil, due to the action of the front clamping mechanism 4, the first piston rod 21 has a tendency to move backward relative to the second piston rod 31, but due to the presence of the clamped object, the clamping mechanism 4 is hindered and cannot continue to be retracted, thereby enabling the clamping mechanism 4 to maintain the state of continued clamping. Until the oil line pressure of the third oil chamber 14 gradually rises to the opening pressure of the overflow valve B 58, the overflow valve B 58 is turned on to return the oil line, and the first piston rod 21 and the second piston rod 31 can retract backward while the clamping mechanism 4 remains clamped.

[0055] The release principle of the clamping mechanism 4 is as follows: switch the three-position four-way valve 53 to the right position, switch the two-position two-way valve 56 to the right position, and maintain the two-position three-way valve A 54 and the two-position three-way valve B 55 in place. At this time, the fourth oil chamber 15 is filled with oil, the first oil chamber 12 and the third oil chamber 14 return to oil, and the second oil chamber 13 is inactive, thereby achieving the extension of the first piston rod 21, the second piston rod 31 cannot move, and thereby achieving the release action of the clamping mechanism 4.

[0056] Although the embodiments of the utility model have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the utility model, and the ordinary skilled in the art can change, modify, replace and transform the above-mentioned embodiments within the scope of the utility model without departing from the principles and purposes of the utility model, and all these changes should belong to the protection scope of the utility model claim.

Claims

1. An oil cylinder type clamping device characterized by comprising: The utility model relates to a hydraulic cylinder, comprising: a cylinder body (1) having a first chamber and a second chamber which are not in communication with each other; a first piston part (2) reciprocally movable in the first chamber and separating the first chamber into a first oil chamber (12) and a second oil chamber (13), the first oil chamber (12) being provided with a first oil port (16), the second oil chamber (13) being provided with a second oil port (17), the first piston part (2) being connected at one end thereof facing the first oil chamber (12) with a first piston rod (21) having a hollow cavity, the first piston rod (21) extending out of the end of the cylinder body (1) at an end thereof distal to the first piston part (2), the outer edge of the first piston rod (21) sealingly engaging the end of the cylinder body (1), the first piston rod (21) being arranged to reciprocate through the end of the cylinder body (1); a second piston part (3) reciprocally movable in the second chamber and separating the second chamber into a third oil chamber (14) and a fourth oil chamber (15), the third oil chamber (14) being provided with a third oil port (18), the fourth oil chamber (15) being provided with a fourth oil port (19), the second piston part (3) being connected at one end thereof facing the third oil chamber (14) with a second piston rod (31), the second piston rod (31) extending out of the end of the cylinder body (1) from the hollow cavity of the first piston rod (21) at an end thereof distal to the second piston part (3) after sealingly passing through the second chamber, the outer edge of the second piston rod (31) sealingly engaging the first piston part (2), and the second piston rod (31) being arranged to reciprocate in the hollow cavity after passing through the first piston part (2); a clamping mechanism (4) comprising two clamping arms (41) which are arranged to be openable and closable, the middle portions of the two clamping arms (41) being rotatably connected to the end of the first piston rod (21) distal to the first piston part (2), respectively, and the tail portions of the two clamping arms (41) being rotatably connected to the end of the second piston rod (31) distal to the second piston part (3) through a linkage structure.

2. The oil cylinder type clamping device according to claim 1, characterized by The radius of the first piston rod is R1, and the outer radius of the second piston rod is R2, R2 = sqrt(2) * R1.

3. The oil cylinder type clamping device according to claim 1, characterized by The first oil port (16), the second oil port (17), the third oil port (18) and the fourth oil port (19) are arranged at the same side position of the cylinder body (1).

4. The oil cylinder type clamping device according to claim 1, characterized by The linkage structure comprises two linkages (44), the middle portions of the two clamping arms (41) are respectively provided with first hinged joints (42), the tail portions of the two clamping arms (41) are respectively provided with second hinged joints (43), the driving end of the second piston rod (31) is provided with a third hinged joint (45), the two first hinged joints (42) are respectively hinged to the two driving ends of the first piston rod (21), and the two linkages (44) are respectively hinged at one end thereof distal to the second hinged joints (43) to the third hinged joint (45) on the driving end of the second piston rod (31).

5. The oil cylinder type clamping device according to claim 1, characterized by The oil cylinder body (1) is provided with an oil cylinder hole through which the first piston rod (21) extends out of the end of the oil cylinder body (1), and a first sealing element is arranged in the oil cylinder hole and sealingly engages the inner side of the first piston rod (21), and the first piston rod (21) is arranged to reciprocate through the first sealing element.

6. The oil cylinder type clamping device according to claim 1, characterized by The first piston part (2) is provided with a piston hole through which the second piston rod (31) extends into the hollow cavity, and a second sealing element is arranged in the piston hole and sealingly engages the inner side of the second piston rod (31), and the second piston rod (31) is arranged to reciprocate through the second sealing element.

7. The oil cylinder type clamping device according to claim 1, characterized by The oil cylinder body (1) is internally provided with a partition part (11) that divides the inside of the oil cylinder body (1) into a first cavity and a second cavity, and the partition part (11) is provided with a partition hole through which one end of the second piston rod (31) away from the second piston part (3) extends into the second oil cavity (13), and a third sealing element is arranged in the partition hole and sealingly engages the inner side of the second piston rod (31), and the second piston rod (31) is arranged to reciprocate through the third sealing element.

8. The oil cylinder type clamping device according to claim 1, characterized by The two clamping arms (41) are the same in size and shape and are symmetrically arranged with respect to the second piston rod (31), and the head of each clamping arm (41) is provided with a clamping part (46) for clamping a workpiece.

9. The oil-hydraulic clamping device according to any one of claims 1 - 8, characterized in that The oil circuit control system (5) for controlling the extension and retraction of the first piston rod (21) and the second piston rod (31) is also included, and the oil circuit control system (5) comprises an oil supply device (51), an oil pump (52), and a three-position four-way valve (53), the input end of the oil pump (52) is connected with the oil supply device (51), the output end of the oil pump (52) is in communication with the P oil port of the three-position four-way valve (53), the T oil port of the three-position four-way valve (53) is in communication with the oil supply device (51), the A oil port of the three-position four-way valve (53) is in communication with the second oil port (17) and the fourth oil port (19) respectively, and the B oil port of the three-position four-way valve (53) is in communication with the first oil port (16) and the third oil port (18) respectively.

10. The oil cylinder type clamping device according to claim 9, characterized by The oil path control system (5) further comprises a two-position three-way valve A (54), a two-position three-way valve B (55), a two-position two-way valve (56), a relief valve A (57), and a relief valve B (58), the input end of the two-position three-way valve A (54) and the input end of the two-position three-way valve B (55) are both in communication with the B oil port of the three-position four-way valve (53), the output end of the two-position three-way valve A (54) is in communication with the third oil port (18), the output end of the two-position three-way valve B (55) is in communication with the first oil port (16), the input end of the two-position two-way valve (56) is in communication with the A oil port of the three-position four-way valve (53), the output end of the two-position two-way valve (56) is in communication with the second oil port (17), the output end of the relief valve A (57) is in communication with the oil port of the two-position three-way valve A (54), the input end of the relief valve A (57) is in communication with the third oil port (18), the output end of the relief valve B (58) is in communication with the oil port of the two-position three-way valve B (55), and the input end of the relief valve B (58) is in communication with the first oil port (16).

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