Crusher buffer cylinder

Abstract

The present invention discloses a buffer oil cylinder of a crusher, comprising a cylinder body, a piston installed in the cylinder body, and a cylinder head with an oil port installed at each of the two ends of the cylinder body, wherein the second cylinder head of the two cylinder heads has a center hole, and a push rod adapted to the piston protrudes from the center hole, and a plunger valve is provided on each of the two cylinder heads or a valve block equipped with a given cylinder head, and the plunger valve is used for opening and closing the oil port; the valve stem of the plunger valve is perpendicular to the end face of the piston and is actuated by the piston; the portion of the flow channel adapted to the oil port where the plunger valve is installed is perpendicular to the valve stem; wherein the plunger valve is provided with a reset device for its plunger that is opposite to the actuation direction of the piston. The buffer oil cylinder of the crusher according to the present invention can effectively reduce hydraulic shock and mechanical shock.

Description

Technical Field

[0001] The invention relates to an oil cylinder with a buffer device, which is specially used for crushing waste. Background Art

[0002] The working environment of the oil cylinder equipped with the crusher is harsh, such as the oil cylinder of the crusher disclosed in the Chinese patent document CN105298976A and the oil cylinder disclosed in the Chinese patent document CN107975514A. Since the working pressure of the hydraulic oil adapted to the oil cylinder is usually relatively large, according to the provisions of the "Mechanical Design Manual", the working pressure of the hydraulic oil is divided into five types: low pressure, medium pressure, medium-high pressure, high pressure and ultra-high pressure. Even for low pressure, its magnitude is MPa level, that is, less than 10MPa, and the working pressure of the oil cylinder used in the crusher is usually in the medium pressure or medium-high pressure range.

[0003] Hydraulic shock and mechanical shock are two inherent problems in the use of hydraulic cylinders. According to the definition of the Mechanical Design Manual, hydraulic shock refers to the pressure increase caused by the sudden stop of the fluid in the pipeline when the valve in the pipeline is suddenly closed. This pressure increase will cause great damage to the hydraulic system. The magnitude of hydraulic shock is positively correlated with the speed of valve closing and the working pressure of the hydraulic system. Mechanical shock is comparable to other types of mechanical shock, that is, the mechanical impact between the piston of the cylinder and the cylinder head after the cylinder is in place. This mechanical impact causes greater damage to the cylinder body itself, but has no effect on other hydraulic components; at the same time, mechanical impact will also generate noise.

[0004] Chinese patent document CN108757632A discloses a pneumatic cylinder. Compared with a hydraulic cylinder, the pneumatic cylinder has a fast response speed and is prone to generate greater noise. However, due to the low working pressure, the impact of the pneumatic system is relatively weak. In order to overcome the noise generated by the mechanical impact of the cylinder itself, in this patent document, a piston with a hollow structure is used, and a hollow structure is provided on the end cover on the rodless cavity side. The compression generated by the collision between the two plays a buffering role, thereby reducing noise. However, this structure will have a greater impact on the stop control. For hydraulic cylinders with relatively high working pressures, it is difficult to control the compression of this buffer structure, so that the working stroke of the piston cannot be accurately controlled.

[0005] Chinese patent document CN208281275U discloses an oil cylinder which also adopts a buffering method, that is, a buffer is arranged at the bottom of the cylinder body. Due to the existence of the buffer, there will inevitably be a problem of working stroke control accuracy.

[0006] In contrast, Chinese patent document CN109340216A discloses a buffer oil cylinder based on valve control, in which the piston divides the oil chamber into a first oil chamber and a second oil chamber, and a pair of one-way valves are provided on the piston, one of which is connected based on the actuation generated by the pressure against the left end cover, and the other one-way valve is connected based on the actuation generated by the pressure against the right end cover, so that at the two fulcrums of the piston movement, the presence of the conducting part on the piston is equivalent to increasing the oil leakage, causing the piston movement speed to slow down, thereby reducing the impact force. Constructing a one-way valve on the piston will significantly increase the thickness of the piston, which will cause relatively great difficulties in both the assembly of the piston and the design of the working stroke. Summary of the invention

[0007] In view of this, an object of the present invention is to provide a buffer cylinder for a crusher which can effectively reduce hydraulic shock and mechanical shock.

[0008] In an embodiment of the present invention, a buffer oil cylinder of a crusher is provided, comprising a cylinder body, a piston installed in the cylinder body, and a cylinder head with an oil port installed at each end of the cylinder body, wherein the second cylinder head of the two cylinder heads has a central hole, and a push rod adapted to the piston protrudes from the central hole, and a plunger valve is respectively provided on the two cylinder heads or a valve block equipped with a given cylinder head, and the plunger valve is used for opening and closing the oil port;

[0009] The valve stem of the plunger valve is perpendicular to the end face of the piston and is actuated by the piston;

[0010] The portion of the flow passage adapted to the oil port for installing the plunger valve is perpendicular to the valve stem;

[0011] The plunger valve is provided with a reset device for its plunger which is opposite to the actuation direction of the plunger by the piston.

[0012] Optionally, the first cylinder head of the two cylinder heads serves as a mounting base for the first plunger valve of the two plunger valves;

[0013] The first cylinder head is provided with two blind holes perpendicular to the end surface of the first cylinder head, one blind hole is configured as a first valve cavity of a first plunger valve, and the other blind hole is configured as a first part of a first oil passage of a first oil port provided in the first cylinder head;

[0014] The first oil passage comprises a second portion communicating with the two blind holes, and the second portion is perpendicular to the two blind holes; the portion communicating with the second portion of the first oil port is the third portion.

[0015] Optionally, the aperture of the third portion is larger than the aperture of the second portion;

[0016] The third portion extends to the side of the valve cavity where the first portion is located.

[0017] Optionally, the second cylinder head of the two cylinder heads is provided with a valve block, the valve block is provided with an axial through hole for the push rod to pass through, and the through hole diameter is larger than the push rod diameter to form a first channel between the through hole wall and the push rod;

[0018] The valve block is provided with a second valve cavity on one side of the first channel, serving as the valve cavity of the second plunger valve of the two plunger valves;

[0019] A communication channel is provided for communicating the second valve chamber with the first channel, and the communication channel is perpendicular to the valve stem.

[0020] Optionally, the valve block and the cylinder body are interference fit; and the valve block is made of an elastic material with a compression rate of 1% to 4%.

[0021] Optionally, a buffer spring is provided on a side of the piston facing the valve block, or a side of the valve block facing the piston;

[0022] The buffer spring is a conical spring, the axial projection of the conical spring on the piston is a vortex line, and adjacent turns of the vortex line are just in contact or disengaged.

[0023] Optionally, the reset device is a reset spring.

[0024] Optionally, one of the two ends of the same plunger is supported by the return spring, and the other end is adapted to be equipped with a retaining spring.

[0025] Optionally, the cylinder body and the cylinder head are connected by a flange.

[0026] Optionally, the aperture of the portion of the oil passage adapted to the oil port where the plunger valve is mounted is smaller than the working stroke of the plunger.

[0027] In the embodiments of the present invention, it is understandable that before the piston contacts the valve stem of the plunger, the plunger valve must be open, otherwise the piston cannot move. In addition, in the field of mechanics, it is understandable that the opening and closing of the plunger is a process in which the opening gradually changes. In other words, when the valve stem is acted upon by the piston, the plunger valve gradually closes, and accordingly, the speed of the piston becomes slower and slower until it stops. This is a gradual process, which is not based on the buffering of the piston by the buffer component, but is based on the gradual cutoff of the hydraulic circuit. The accuracy of the working stroke of the buffer cylinder is not affected. For mechanical shock and hydraulic shock, since the closure of the oil outlet is gradual, it can effectively alleviate mechanical shock and hydraulic shock, and can effectively protect the hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic cross-sectional structure diagram of a buffer oil cylinder in one embodiment.

[0029] In the figure: 1. first cylinder head, 2. first oil port, 3. first oil channel, 4. first spring, 5. first plunger, 6. second spring, 7. second oil channel, 8. first positioning rod, 8. oil chamber, 10. sealing ring, 11. sealing ring, 12. piston, 13. conical spring, 14. second positioning rod, 15. third spring, 16. second plunger, 17. second oil port, 18. push rod, 19. second cylinder head, 20. sealing ring, 21. sealing ring, 22. fourth spring, 23. connecting oil channel, 24. shaft hole, 25. valve block, 26. valve body. DETAILED DESCRIPTION

[0030] Refer to the instruction manual Figure 1 There are two oil ports in the figure, namely the first oil port 2 and the second oil port 17 shown in the figure. The oil cylinder shown in the figure is a double-acting cylinder, that is, the first oil port 2 and the second oil port 17 serve as both the oil inlet and the oil outlet. In the field of hydraulic cylinder technology, such two oil ports are usually defined as port A and port B.

[0031] For the first plunger valve contained in the first plunger 5 in the figure, and the second plunger valve contained in the second plunger 16, it can be understood that under the condition that the piston 12 is not in contact with the corresponding valve stem, the two plunger valves must be open, otherwise the oil chamber 9 is closed and the piston 12 cannot move.

[0032] About the valve stem, Figure 1 A positioning rod is used to represent, for example, the first positioning rod 8 and the second positioning rod 14 shown in the figure, and the positioning rod is used to represent the valve stem, which is used to determine the working stroke of the plunger in some applications, and therefore belongs to functional positioning.

[0033] In addition, regarding the hydraulic cylinder, it is different from the gas cylinder. The hydraulic cylinder runs relatively smoothly, and at the same time, its running speed is relatively low. In particular, unlike the gas cylinder, the working medium of the gas cylinder is a gas with a relatively large compression ratio, while the working medium of the hydraulic cylinder is a liquid with an almost negligible compression ratio. In the hydraulic system, for example, the speed of the hydraulic cylinder is directly related to the flow rate of the hydraulic circuit. The plunger valve is a valve that gradually closes or opens, and the opening of the corresponding plunger valve is directly related to the amount of pressure on the first positioning rod 8, for example. The more pressure is applied, the smaller the opening. Relatively speaking, the smaller the opening, the smaller the flow of hydraulic oil, and the slower the speed of the piston 12, so that the piston gradually stops, effectively reducing hydraulic shock and mechanical shock.

[0034] Specifically, Figure 1 The buffer cylinder of a crusher shown is placed horizontally. As for the cylinder body 26 (also called cylinder barrel), it is a cylindrical structure as a whole, so it has certain axial, radial and circumferential directions. The piston 12 matched with it forms a moving pair with the cylinder body 26. The main body of the conventional structure of the piston 12 is a short cylindrical structure.

[0035] Both ends of the cylinder body 26 are sealed by cylinder heads, which are adapted to the cylindrical structure of the cylinder body 26. The sealing needs to be completed by two cylinder head adapter fasteners (mostly bolts) and seals (mostly rubber sealing rings). Specifically, it can be seen that the first cylinder head 1 is located at the left end of the cylinder body 26 and the second cylinder head 19 is located at the right end of the cylinder body 26.

[0036] The connection between the cylinder head and the cylinder body 26 is usually a flange connection, and the flange is provided with at least three bolt holes, but usually no more than six, and the bolt connection is convenient for disassembly and assembly.

[0037] Figure 1 The connection between the cylinder head and the cylinder body 26 is not specifically shown, and the assembly structure between the two belongs to the conventional structure in the field and will not be repeated here.

[0038] The conventional structure of the hydraulic cylinder can also be seen in the piston 12 and the push rod 18 and their assembly structure, wherein the push rod 18 is referred to as a piston rod in more applications, and can be fixedly connected to the piston 12 or formed into an integral structure.

[0039] Generally speaking, it is relatively difficult to open the oil port on the cylinder body 26 of the double-acting cylinder. Therefore, in more applications, the oil port is opened on the cylinder head, such as Figure 1 In the embodiment, a first oil port 2 is formed on the first cylinder head 1, and a second oil port 17 is formed on the second cylinder head 19.

[0040] The second cylinder cover 19 has a central hole, and a push rod 18 adapted to the piston 12 protrudes from the central hole. Accordingly, the push rod 18 and the second cylinder cover 19 are in sliding fit, and a sealing structure needs to be provided on the sliding surface, such as Figure 1 In the figure, there is one sealing ring 20 and two sealing rings 21, wherein the sealing ring 20 is an oil seal and the sealing ring 21 is a dust seal.

[0041] As for the two plunger valves, one may be provided on each of the two cylinder heads, or may be provided on an additional structure, such as Figure 1 The valve block 25 shown in FIG.

[0042] The piston 12 divides the oil chamber 9 into Figure 1 The left and right parts shown in the figure, wherein the first oil port 2 is connected to the left oil chamber on the left through the first oil port oil passage, and the second oil port 17 is connected to the right oil chamber on the right through the second oil port oil passage. Of the two plunger valves mentioned above, one is used for the opening and closing control of the first oil port oil passage, and the other is used for the opening and closing control of the second oil port oil passage.

[0043] exist Figure 1In the structure shown, the valve stems of the two plunger valves, namely the first positioning rod 8 and the second positioning rod 14 shown in the figure, extend into the corresponding oil chamber in the normal direction of the corresponding valve cover. The length of the valve stem extending out of the corresponding valve cover determines the working stroke of the corresponding plunger valve, which can be easily designed by technicians in this field.

[0044] Correspondingly, at the two end sections of the working stroke of the piston 12, the piston 12 contacts the corresponding valve stem and then pushes the valve stem forward, thereby driving the corresponding plunger forward, gradually closing the corresponding oil port and oil channel until it is completely closed. During this process, the closing of the oil port and oil channel is gradual.

[0045] After the piston 12 is out of contact with the corresponding valve stem, the corresponding oil port oil passage should be opened, so the corresponding plunger valve should be automatically reset. The device for automatic reset is recorded as the reset device. Figure 1 In the structure shown, for example, a first spring 4 and a fourth spring 22 are provided to act in a direction opposite to the actuation direction of the piston 12 on the corresponding valve stem, thereby resetting the acted plunger.

[0046] In some embodiments, Figure 1 The cylinder head on the left, namely the first cylinder head 1 shown in the figure, directly serves as a mounting base for the first plunger valve of the two plunger valves, and the first oil port oil passage is directly formed on the first cylinder head 1 .

[0047] since Figure 1 As viewed from the right side of the figure, two blind holes are opened on the first cylinder head 1 perpendicular to the right end surface of the first cylinder head 1, one blind hole is configured as the first valve cavity of the first plunger valve, and the other blind hole is configured as the first part of the first oil passage of the first oil port opened by the first cylinder head 1, that is, Figure 1 The horizontal part of the .

[0048] The blind hole configured as the first valve cavity is deeper than the blind hole configured as the first portion. Furthermore, the first oil passage, namely the aforementioned first oil port oil passage, includes a second portion connecting the two blind holes, namely Figure 1 The upper first cylinder head is located at the vertical oil passage portion below the first plunger 5, and the second portion is perpendicular to the two blind holes; the portion where the first oil port is connected to the second portion is the third portion. In this structure, the lower side of the first plunger 5 gradually closes the second portion during the leftward movement of the first plunger 5, thereby gradually closing the oil passage of the first oil port.

[0049] Correspondingly, when the piston 12 moves rightward, under the elastic force of the first spring 4, the first plunger 5 gradually returns to the rightward position, and the shielding of the second part becomes smaller and smaller.

[0050] exist Figure 1In the structure shown, the aperture of the third part is larger than that of the second part, and the second part is offset to the right, so that a shoulder exists between the second part and the third part, which is beneficial for arranging the first spring 4 and facilitating setting the first plunger 5.

[0051] Accordingly, the third portion extends to the side of the valve chamber where the first portion is located.

[0052] Different from the first cylinder head 1 , the second cylinder head 19 of the two cylinder heads is equipped with a valve block 25 , which has an axial through hole 24 for the push rod 18 to pass through, and the through hole 24 has a diameter larger than the diameter of the push rod 18 to form a first channel between the through hole wall and the push rod 18 .

[0053] The valve block 25 has a second valve cavity formed on one side of the first passage, serving as a valve cavity of the second plunger valve of the two plunger valves.

[0054] A communication channel is provided for communicating the second valve chamber with the first channel, and the communication channel is perpendicular to the valve stem.

[0055] Relatively speaking, the speed of the piston 12 during the working stroke is faster than the speed of the return stroke. In other words, the impact generated during the working stroke is stronger. Therefore, the valve block 25 and the cylinder body 26 are interference-fitted, and the valve block 25 is made of an elastic material with a compression rate of 1% to 4%. After the piston 12 moves to the right, it can be better buffered by the valve block 25.

[0056] In addition, the compression rate of ordinary rubber can meet the aforementioned compression rate requirements. Under this condition, the compression amount of the valve block 25 is relatively limited and does not affect the structure of the second plunger valve; especially under the aforementioned interference fit, the valve block 25 has been partially pre-compressed.

[0057] exist Figure 1 In the structure shown, a buffer spring is provided on the side of the piston 12 facing the valve block 25, or on the side of the valve block 25 facing the piston 12, such as Figure 1 The conical spring 13 shown in FIG.

[0058] Furthermore, the axial projection of the conical spring 13 on the piston is a vortex line, and adjacent turns of the vortex line are just in contact or disengaged, so that after the conical spring 13 is pressed together, it is roughly a sheet-like structure, and the thickness of the sheet-like structure is determined. Therefore, when the conical spring 13 is set, it will not affect the working stroke of the hydraulic cylinder.

[0059] In some embodiments, one end of the two ends of the same plunger supports the return spring, and the other end is adapted to be equipped with a holding spring. Specifically referring to the first spring 4 and the second spring 6 in the figure, the second spring 6 can make the first plunger 5 in a relatively suitable position.

[0060] In a preferred embodiment, the hole diameter of the portion of the oil passage adapted to the oil port equipped with the plunger valve is smaller than the working stroke of the plunger.

Claims

1. A buffer oil cylinder for a crusher, comprising a cylinder body, a piston installed in the cylinder body, and a cylinder head with an oil port installed at each end of the cylinder body, wherein the second cylinder head of the two cylinder heads has a center hole, and a push rod adapted to the piston protrudes from the center hole, and is characterized in that: A plunger valve is provided on each of the two cylinder heads or the valve block mounted on a given cylinder head, and the plunger valve is used for opening and closing the oil port; The valve stem of the plunger valve is perpendicular to the end face of the piston and is actuated by the piston; The portion of the flow passage adapted to the oil port for installing the plunger valve is perpendicular to the valve stem; Wherein, the plunger valve is provided with a reset device for its plunger which is opposite to the actuation direction of the piston; The first cylinder head of the two cylinder heads serves as a mounting base for the first plunger valve of the two plunger valves; The first cylinder head is provided with two blind holes perpendicular to the end surface of the first cylinder head, one blind hole is configured as a first valve cavity of a first plunger valve, and the other blind hole is configured as a first part of a first oil passage of a first oil port provided in the first cylinder head; The first oil passage includes a second portion communicating with the two blind holes, the second portion being perpendicular to the two blind holes; the portion communicating with the second portion of the first oil port is the third portion; The second cylinder head of the two cylinder heads is provided with a valve block, the valve block is provided with an axial through hole for the push rod to pass through, and the through hole diameter is larger than the push rod diameter to form a first channel between the through hole wall and the push rod; The valve block is provided with a second valve cavity on one side of the first channel, serving as the valve cavity of the second plunger valve of the two plunger valves; A communication channel is provided for communicating the second valve chamber with the first channel, and the communication channel is perpendicular to the valve stem.

2. The buffer cylinder of the crusher according to claim 1, characterized in that: The aperture of the third portion is larger than the aperture of the second portion; The third portion extends to the side of the valve cavity where the first portion is located.

3. The buffer cylinder of the crusher according to claim 1, characterized in that: The valve block and the cylinder body have an interference fit; and the valve block is made of elastic material with a compression rate of 1% to 4%.

4. The buffer cylinder of the crusher according to claim 1, characterized in that: A buffer spring is provided on the side of the piston facing the valve block, or on the side of the valve block facing the piston; The buffer spring is a conical spring, the axial projection of the conical spring on the piston is a vortex line, and adjacent turns of the vortex line are just in contact or disengaged.

5. The buffer cylinder of the crusher according to claim 1, characterized in that: The reset device is a reset spring.

6. The buffer cylinder of the crusher according to claim 5, characterized in that: One end of the two ends of the same plunger supports the return spring, and the other end is adapted to be equipped with a holding spring.

7. The buffer cylinder of the crusher according to claim 1, characterized in that: The cylinder body and the cylinder head are connected by flange.

8. The buffer cylinder of the crusher according to claim 1, characterized in that: The aperture of the portion of the oil passage adapted to the oil port and equipped with the plunger valve is smaller than the working stroke of the plunger.

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