Hydraulic oil cylinder convenient for stroke adjustment

Abstract

The invention relates to the technical field of hydraulic oil cylinders, in particular to a hydraulic oil cylinder facilitating stroke adjustment. The cylinder barrel is provided with a rear cylinder cover and a front cylinder cover, the piston is arranged in the cylinder barrel in a sliding mode, one end of the piston is fixedly connected with a piston rod, and a through groove penetrating through the piston is formed in the piston rod; the device further comprises a telescopic limiting mechanism and a one-way pressure release valve arranged on the telescopic limiting mechanism. According to the hydraulic oil cylinder convenient to adjust the stroke, the telescopic limiting mechanism is arranged in the cylinder barrel, the stroke of the piston is limited through the length change of the telescopic limiting mechanism, and therefore the problem that the external space is occupied is avoided. The length of the telescopic limiting mechanism is adjusted through changes of the pressure of oil in the cylinder barrel, only movement of the piston rod needs to be limited in the adjusting process, and therefore the problem that the limiting stroke of a built-in limiting mechanism is difficult to adjust is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic oil cylinders, in particular to a hydraulic oil cylinder which is convenient for stroke adjustment. Background Art

[0002] Hydraulic cylinders are widely used as hydraulic actuators. The stroke of a hydraulic cylinder's piston rod is determined by the effective working length of the cylinder barrel and the piston length. Typically, the stroke is calculated by subtracting the piston length from the effective working length of the cylinder barrel. Traditional hydraulic cylinders have a constant effective working length and piston length, so their stroke is immutable.

[0003] However, in some special scenarios where the piston rod does not need to be fully extended (for example, the piston rod only needs to be extended two-thirds of the way), a limit mechanism is currently installed on the hydraulic cylinder to limit the stroke of the piston rod and prevent the piston rod from being fully extended. Currently, there are two types of mechanical limit mechanisms:

[0004] One is an external limit mechanism, which uses a double-rod oil cylinder and installs an adjustable nut on the rear rod to adjust the forward position of the working part. Although this mechanism is more flexible in adjustment, on the one hand, the piston rod must be very long (usually more than three times the length of the single-rod piston); on the other hand, the rear rod usually passes through the rear cylinder head and extends into the external environment, resulting in a certain amount of external space.

[0005] The other is a built-in limit mechanism, which forms a hard limit by fixing the limit ring between the front cylinder cover and the piston to limit the extension length of the piston rod. Since this hard limit is mounted on the piston rod, when adjusting the stroke, the entire cylinder can only be disassembled and replaced with a limit ring of a new length to adjust the new stroke. Summary of the Invention

[0006] The object of the present invention is to provide a hydraulic cylinder that is easy to adjust the stroke. It solves the problems raised in the above-mentioned background technology by arranging a telescopic limit mechanism inside the cylinder barrel and utilizing the oil pressure in the cylinder barrel to adjust the limit stroke of the piston, namely, the problem that the external limit mechanism occupies external space and the internal limit mechanism is difficult to adjust the limit stroke.

[0007] To achieve the above object, a hydraulic cylinder that is easy to adjust the stroke includes a cylinder barrel having a rear cylinder cover and a front cylinder cover, and a piston slidably arranged inside the cylinder barrel, one end of the piston is fixedly connected to a piston rod, and a through groove is provided inside the piston rod that penetrates the piston;

[0008] It also includes a telescopic limit mechanism and a one-way pressure relief valve provided on the telescopic limit mechanism; one end of the telescopic limit mechanism is fixedly connected to the rear cylinder cover, and the movable end extends into the through groove;

[0009] When the oil pressure in the cylinder drives the one-way pressure relief valve to open, part of the oil in the cylinder enters the telescopic limit mechanism to adjust the overall length of the telescopic limit mechanism;

[0010] The telescopic limiting mechanism is used to limit the movement stroke of the piston through its own length.

[0011] In the above technical solution, the telescopic limiter is set inside the cylinder to reduce the external space occupied. At the same time, when the oil pressure in the cylinder increases, the telescopic limiter can automatically move to the piston under the action of the oil pressure, thereby restricting the piston.

[0012] On this basis, the movable end of the telescopic limit mechanism is connected to a clamping block, and the inner wall surface of the through slot is provided with a protrusion. The clamping block and the protrusion are located on the same movement path, and the distance between the two protrusions is less than the width of the clamping block. In this way, when the clamping block and the protrusion approach each other, they cannot pass over each other, and thus the two blocks each other to limit the piston.

[0013] Furthermore, the telescopic limiting mechanism includes a piston cylinder with an open end and a closed end. The open end of the piston cylinder is fixedly connected to the rear cylinder cover, and the closed end extends into the through groove. A through opening is provided on the side wall of the rear cylinder cover at a position corresponding to the opening of the piston cylinder.

[0014] It also includes a limiting piston rod with one end slidingly arranged in the piston cylinder and the other end penetrating the closed end of the piston cylinder;

[0015] One end of the limiting piston rod is fixedly connected to a clamping block;

[0016] The inner wall surface of the through groove close to one end of the piston is symmetrically provided with protrusions protruding inwards.

[0017] The one-way pressure relief valve includes an oil delivery chamber arranged inside the left end of the piston cylinder and a valve ball located in the oil delivery chamber;

[0018] The oil delivery chamber is connected to the interior of the telescopic limit mechanism through the top opening, and one side is connected to the interior of the piston cylinder;

[0019] The outer diameter of the valve ball is larger than the outer diameter of the top opening of the oil delivery cavity, and an elastic member is provided between the bottom of the valve ball and the bottom of the oil delivery cavity.

[0020] A follower rod is fixedly provided on the top of the valve ball, the top end of the follower rod passes through the opening at the top of the oil delivery cavity and extends to the inner wall surface of the through groove, and a protrusion is provided on the inner wall surface of the through groove;

[0021] The side wall of the rear cylinder cover is threadedly connected with an adjusting bolt which passes through the side wall of the rear cylinder cover.

[0022] In the above, the structure of the telescopic limit mechanism and the one-way pressure relief valve is specifically described. When the one-way pressure relief valve is opened, the oil enters the piston cylinder to push the limit piston rod to move, so that the limit piston rod drives the block to resist the protrusion. Then, due to the one-way action of the one-way pressure relief valve, the limit piston rod cannot be reset, and the oil is difficult to be compressed. Therefore, in this state, the telescopic limit mechanism completes the limitation of the piston.

[0023] In another technical solution, a one-way valve for discharging gas from the piston cylinder is provided inside the through-port of the rear cylinder cover.

[0024] In this technical solution, the one-way valve can prevent the limiting piston rod from being pushed by the piston, thereby preventing the object from being blocked during the process of pushing the object and causing the piston rod to continue to exert a large thrust on the object.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. This stroke-adjustable hydraulic cylinder incorporates a telescopic limiter mechanism within the cylinder barrel. This mechanism's length changes are used to limit the piston's stroke, thus avoiding the problem of occupying external space. Furthermore, the mechanism adjusts its length through changes in the oil pressure within the cylinder barrel, and adjustment only requires limiting the movement of the piston rod. This solves the difficulty of adjusting the stroke limit with a built-in limiter mechanism.

[0027] 2. In the hydraulic cylinder with easy stroke adjustment, the telescopic limit mechanism can not only limit the position of the piston, but also automatically limit the movement of the piston when the piston rod encounters resistance, reducing the distance the piston rod continues to move, thereby reducing the deformation of the object when it is squeezed and improving the integrity of the object. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 Schematic diagram of the cross-sectional structure of the telescopic limiting mechanism of the present invention;

[0030] Figure 3 For the present invention Figure 2 A magnified schematic diagram of the A storage structure;

[0031] Figure 4 It is a structural schematic diagram of the card block of the present invention;

[0032] Figure 5 A schematic diagram of one working state of the telescopic limiting mechanism of the present invention;

[0033] Figure 6It is a structural schematic diagram of the driven rod of the present invention;

[0034] Figure 7 This is a schematic diagram of another working state of the telescopic limiting mechanism of the present invention.

[0035] The meaning of each number in the figure is:

[0036] 100. Cylinder barrel; 101. Rear cylinder head; 102. Front cylinder head; 103. Rear oil delivery port; 104. Front oil delivery port; 105. Piston; 106. Piston rod; 107. Through groove; 108. End cover; 109. Bump; 110. Telescopic limit mechanism; 111. Piston barrel; 112. Limit piston rod; 113. Block; 114. Oil delivery chamber; 115. Valve ball; 116. Support spring; 117. Follower rod; 118. Protrusion; 120. Adjusting bolt; 130. One-way valve; 200. Limiting part. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0038] Aiming at the problem that the external limit mechanism occupies the external space and the internal limit mechanism is difficult to adjust the limit stroke, the present invention provides a hydraulic cylinder that is easy to adjust the stroke, such as Figure 1 As shown, the hydraulic cylinder includes a cylinder barrel 100 and cylinder caps arranged at both ends of the cylinder barrel 100. A piston 105 is slidably arranged inside the cylinder barrel 100. For ease of understanding, Figure 1 The state of the middle cylinder barrel 100 is taken as the standard. Located at the right end of the cylinder barrel 100 is the rear cylinder head 101. A rear oil port 103 is provided on the top of the rear cylinder head 101. Oil enters the right side of the piston 105 through the rear oil port 103 to push the piston 105 to the left. Located at the left end of the cylinder barrel 100 is the front cylinder head 102. A front oil port 104 is provided on the top of the front cylinder head 102. Oil enters the left side of the piston 105 through the rear oil port 103 to push the piston 105 to the left. The left end of the piston 105 is fixedly connected to the piston rod 106. The left end of the piston rod 106 slides through the front cylinder head 102. The penetration part needs to be sealed (usually a sealing component is provided) to prevent oil from leaking through the inner wall surface of the front oil port 104 and the outer peripheral surface of the through groove 107.

[0039] A through slot 107 is provided inside the piston rod 106, the right end of which extends through the entire piston 105. This can also be understood as: through slots 107 are provided inside both the piston rod 106 and the piston 105, and the two through slots 107 are interconnected. The hydraulic cylinder also includes a telescopic limit mechanism 110 and a one-way pressure relief valve provided on the telescopic limit mechanism 110. The telescopic limit mechanism 110 is fixedly connected to the side wall of the rear cylinder cover 101, and the movable end of the telescopic limit mechanism 110 extends into the through slot 107, so that the movable end of the telescopic limit mechanism 110 is located in the motion path of the piston 105. When the oil pressure between the piston 105 and the rear cylinder cover 101 drives the one-way pressure relief valve to open, some of the oil between the piston 105 and the rear cylinder cover 101 enters the telescopic limit mechanism 110, thereby adjusting the overall length of the telescopic limit mechanism 110. The telescopic limit mechanism 110 is used to limit the motion stroke of the piston 105 by its own length.

[0040] Specifically, if Figure 2 As shown, the telescopic limiting mechanism 110 includes a piston cylinder 111 with an open right end and a closed left end. In some embodiments, the right end of the piston cylinder 111 is fixed to the left side of the rear cylinder cover 101, and the left end extends into the through groove 107. In addition, the telescopic limiting mechanism 110 also includes a limiting piston rod 112 with a left end (the left end is a piston structure to achieve a sealed connection with the inner wall of the piston cylinder 111) slidingly set in the piston cylinder 111 and a right end passing through the closed end of the piston cylinder 111. At the same time, a block 113 is fixedly set on the left end of the limiting piston rod 112, and then as shown in FIG. Figure 4 As shown, protrusions 109 protruding inward are symmetrically provided on the inner wall surface of the through groove 107 close to one end of the piston 105 , and the distance a1 between the two protrusions 109 is smaller than the width a2 of the clamping block 113 .

[0041] A through opening is provided on the side wall of the rear cylinder cover 101 at a position corresponding to the opening of the piston cylinder 111 .

[0042] In a specific implementation, an end cap 108 is fixedly mounted on the side wall of the piston 105 facing the rear cylinder head 101. The end cap 108 is an annular structure, and the inner diameter of the end cap 108 is the same as the inner diameter of the through groove 107. Then, the protrusion 109 is placed on the inner ring of the end cap 108. This arrangement allows the protrusion 109 to be quickly replaced by replacing the end cap 108 when it becomes worn.

[0043] In this way, combined Figure 2As shown in FIG1 , the piston 105 moves to the left side of the locking block 113 and the end cover 108, and the locking block 113 blocks the end cover 108 through the protrusion 109. Therefore, the piston 105 connected to the end cover 108 will naturally be affected. At this time, the piston 105 cannot continue to move to the left, thereby limiting the position of the piston 105.

[0044] Due to different usage scenarios, the position of the piston 105 limiter also needs to be adaptively adjusted. Therefore, the overall length of the telescopic limiter mechanism 110 cannot be in a fixed state, which is why the piston cylinder 111 needs to be telescopic. The above records the control through the one-way pressure relief valve. The specific control structure and method refer to Figure 3 .

[0045] like Figure 3 As shown, in some embodiments, the one-way pressure relief valve includes an oil delivery chamber 114 arranged inside the left end of the piston cylinder 111 and a valve ball 115 located in the oil delivery chamber 114. The oil delivery chamber 114 is connected to the interior of the telescopic limit mechanism 110 through the top opening and is connected to the interior of the piston cylinder 111 on the right side; the valve ball 115 is connected to the bottom of the oil delivery chamber 114 through a support spring 116 arranged at the bottom, so that the support spring 116 presses the valve ball 115 against the top of the oil delivery chamber 114. At the same time, the outer diameter of the valve ball 115 is larger than the outer diameter of the top opening of the oil delivery chamber 114, thereby achieving the blocking of the top opening of the oil delivery chamber 114.

[0046] Furthermore, a follower rod 117 is fixed to the top of the valve ball 115. The top end of the follower rod 117 passes through the opening at the top of the oil delivery chamber 114 and extends to the inner wall of the through groove 107. A protrusion 118 is also provided on the inner wall of the through groove 107. The protrusion 118 and the follower rod 117 are coaxial. That is, when the protrusion 118 and the follower rod 117 approach each other, the protrusion 118 can push the follower rod 117 downward. Correspondingly, an adjusting bolt 120 is threadedly connected to the side wall of the rear cylinder head 101. The adjusting bolt 120 passes through the side wall of the rear cylinder head 101 and is used to limit the movement of the piston 105 to the side wall of the rear cylinder head 101.

[0047] In other words, by disposing the telescopic limiter 110 within the cylinder 100, the travel of the piston 105 is limited by the change in the length of the telescopic limiter 110, thereby avoiding the problem of occupying external space. Furthermore, the telescopic limiter 110 adjusts its own length by changes in the oil pressure within the cylinder 100, and the adjustment process only requires limiting the movement of the piston rod 106, thus resolving the difficulty of adjusting the travel limit of an internal limiter.

[0048] The working principle of the hydraulic cylinder is described in detail below:

[0049] like Figure 5 As shown, when limiting the stroke of the piston 105, the oil is first fed into the area c through the rear oil delivery port 103. The oil in the area c pushes the piston 105 to move. When the piston 105 moves to the position where the limit is required (for example, Figure 5 The piston 105 is positioned in the middle of the valve body 106, and resistance is applied at the end of the piston rod 106 (i.e., position b) to limit the piston 105 from moving further to the left. At this time, the oil pressure in area c begins to increase, thereby overcoming the elasticity of the support spring 116, causing the valve ball 115 to move downward to open the opening at the top of the oil delivery chamber 114. Then, part of the oil in area c flows into the piston cylinder 111 through the oil delivery chamber 114 (refer to Figure 5 The oil drives the limit piston rod 112 to move to the right (refer to the black arrow in the figure). Figure 5 When the pressure in area C equals the pressure in piston cylinder 111, valve ball 115 at the top of support spring 116 returns to its original position, disconnecting the inner wall of piston cylinder 111 from area C. This prevents the oil in piston cylinder 111 from draining, thus fixing the overall length between limiter piston rod 112 and piston cylinder 111.

[0050] After the adjustment is completed, whenever the piston 105 moves to Figure 5 When the piston 105 is in the middle position, the piston 105 will be blocked by the block 113, thereby preventing the piston 105 from moving further.

[0051] When there is no need to limit the piston 105, refer to Figure 6 As shown, by turning the adjusting bolt 120, the adjusting bolt 120 moves to the right. Figure 2 As shown, after the front cylinder cover 102 is screwed, the distance d between the end cover 108 and the rear cylinder cover 101 becomes smaller, which means that the piston 105 can move further to the left, thereby driving the protrusion 118 to move to the bottom of the driven rod 117 during the leftward movement. At this time, the driven rod 117 drives the valve ball 115 to move downward to open the oil delivery chamber 114, and then pushes the limiting piston rod 112 to the left through an external tool (such as a push rod), and the limiting piston rod 112 can be reset at this time.

[0052] In addition, in order to improve the efficiency of resetting, a reset spring can also be set at position e, one end of the reset spring is connected to the limiting piston rod 112, and the other end is connected to the inside of the piston cylinder 111, which is used to push the limiting piston rod 112 to move to the left.

[0053] When you need to exit Figure 6In the state shown, the limiting piston rod 112 can be pushed leftward by an external tool to prevent the limiting piston rod 112 from moving leftward. At this time, when the oil enters the cylinder 100 through the rear oil delivery port 103, since the limiting piston rod 112 cannot move, the oil in the telescopic limiting mechanism 110 will only push the piston 105 to the left. At this time, the protrusion 118 disengages from the driven rod 117, and the valve ball 115 at the top of the support spring 116 returns to its original position. Of course, it is also possible to not block the limiting piston rod 112 and directly use the oil to push the piston 105 to the left.

[0054] Furthermore, the hydraulic cylinder of the present invention not only has a stroke adjustment function, but also has a protection function.

[0055] like Figure 7 As shown, when the piston rod 106 is used to push an object, assuming the square object at the top is in a normal state, the piston rod 106 pushes the normal object to the side wall of the limiter 200 a distance d1; the square object at the bottom is in an abnormal state, and the abnormal object is pushed to the side wall of the limiter 200 a distance d2. It can be seen that the distance d2 does not reach the set distance of the piston rod 106. In this case, the piston rod 106 will continue to extend, thereby crushing the abnormal object.

[0056] When the hydraulic cylinder of the present invention faces this scenario, the unusual object will resist the movement of piston rod 106, increasing the oil pressure in area C. At this point, some of the oil in area C flows through oil delivery chamber 114 into piston cylinder 111, causing a pressure relief operation and reducing the pressure on the object. The oil then drives the limiting piston rod 112 to move rightward, which in turn drives the block 113 against the sidewall of protrusion 109, limiting the position of piston 105 and preventing it from moving further to the left. During this process, the unusual object will only experience slight compression deformation, without experiencing significant compression deformation.

[0057] To enhance the limiting effect, in some embodiments, a one-way valve 130 may be provided within the opening of the rear cylinder head 101. This allows gas within the piston cylinder 111 to be discharged only through the one-way valve 130. Consequently, after the limiting piston rod 112 moves rightward, it cannot move leftward, further enhancing the stability of the locking block 113 in limiting the position of the piston 105. Furthermore, a threaded connection is provided between the one-way valve 130 and the opening to facilitate removal of the one-way valve 130.

[0058] In summary, the telescopic limit mechanism 110 can not only limit the position of the piston 105, but also automatically limit the movement of the piston 105 when the piston rod 106 encounters resistance, reducing the distance that the piston rod 106 continues to move, thereby reducing the deformation of the object when it is squeezed and improving the integrity of the object.

[0059] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A hydraulic cylinder convenient for stroke adjustment, comprising a cylinder barrel (100) having a rear cylinder cover (101) and a front cylinder cover (102), and a piston (105) slidably arranged inside the cylinder barrel (100), wherein one end of the piston (105) is fixedly connected to a piston rod (106), characterized in that: The piston rod (106) is provided with a through groove (107) penetrating the piston (105); It also includes a telescopic limiting mechanism (110) and a one-way pressure relief valve arranged on the telescopic limiting mechanism (110); one end of the telescopic limiting mechanism (110) is fixedly connected to the rear cylinder cover (101), and the movable end extends into the through groove (107); When the oil pressure in the cylinder (100) drives the one-way pressure relief valve to open, part of the oil in the cylinder (100) enters the interior of the telescopic limiting mechanism (110) to adjust the overall length of the telescopic limiting mechanism (110); The telescopic limiting mechanism (110) is used to limit the movement stroke of the piston (105) through its own length.

2. The hydraulic cylinder with easy stroke adjustment according to claim 1, characterized in that: The movable end of the telescopic limiting mechanism (110) is connected with a clamping block (113), and a protrusion (109) is provided on the inner wall surface of the through groove (107). The clamping block (113) and the protrusion (109) are on the same moving path. When the clamping block (113) and the protrusion (109) approach each other, the two abut against each other.

3. The hydraulic cylinder with easy stroke adjustment according to claim 2, characterized in that: The telescopic limiting mechanism (110) comprises a piston cylinder (111) with an open end and a closed end. The open end of the piston cylinder (111) is fixedly connected to the rear cylinder cover, and the closed end extends into the through groove (107). A through opening is provided on the side wall of the rear cylinder cover (101) at a position corresponding to the opening of the piston cylinder (111). It also includes a limiting piston rod (112) with one end slidingly arranged in the piston cylinder (111) and the other end penetrating the closed end of the piston cylinder (111); One end of the limiting piston rod (112) is fixedly connected to a clamping block (113); A protrusion (109) protruding inward is symmetrically provided on the inner wall surface of the through groove (107) close to one end of the piston (105).

4. The hydraulic cylinder with easy stroke adjustment according to claim 3, characterized in that: The distance between the two protrusions (109) is smaller than the width of the clamping block (113).

5. The hydraulic cylinder with easy stroke adjustment according to claim 3, characterized in that: The one-way pressure relief valve comprises an oil delivery chamber (114) arranged inside the left end of the piston cylinder (111) and a valve ball (115) located in the oil delivery chamber (114); The oil delivery cavity (114) is connected to the interior of the telescopic limiting mechanism (110) through a top opening, and one side is connected to the interior of the piston cylinder (111); The outer diameter of the valve ball (115) is larger than the outer diameter of the top opening of the oil delivery cavity (114), and an elastic member is provided between the bottom of the valve ball (115) and the bottom of the oil delivery cavity (114).

6. The hydraulic cylinder with easy stroke adjustment according to claim 5, characterized in that: The elastic member is a supporting spring (116).

7. The hydraulic cylinder with easy stroke adjustment according to claim 5, characterized in that: A driven rod (117) is fixedly provided on the top of the valve ball (115), and the top end of the driven rod (117) passes through the opening at the top of the oil delivery cavity (114) and extends to the inner wall surface of the through groove (107). A protrusion (118) is provided on the inner wall surface of the through groove (107); The side wall of the rear cylinder cover (101) is threadedly connected with an adjusting bolt (120) that penetrates the side wall of the rear cylinder cover (101).

8. The hydraulic cylinder with easy stroke adjustment according to claim 7, characterized in that: The protrusion (118) and the driven rod (117) are located in the same axis.

9. The hydraulic cylinder with easy stroke adjustment according to claim 3, characterized in that: A one-way valve (130) for discharging gas from the piston cylinder (111) is provided inside the through port of the rear cylinder cover (101).

10. The hydraulic cylinder with easy stroke adjustment according to claim 9, characterized in that: The one-way valve (130) is threadedly connected to the through port.

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