Connecting structure of pressure head and oil cylinder

Abstract

The utility model relates to a connecting structure of a pressure head and an oil cylinder, which comprises the oil cylinder, a piston rod is arranged in the oil cylinder, the end part of the piston rod is a stretching head, and the stretching head is provided with the pressure head; a connecting sleeve is arranged at the rear part of the pressure head; the pressing head is combined with the positioning nut and the cap through the connecting sleeve and is fixed on the extending head; external threads are arranged on one side, close to the cylinder body of the oil cylinder, of the middle part of the extending head after the pressure head is mounted; an internal thread matched with the external thread is arranged in the positioning nut, the external thread is in threaded connection with the internal thread, and the positioning nut is fixed in the middle of the extending head; the positioning nut is not contacted with the pressure head; a locking internal thread is arranged in the connecting sleeve; a connecting external thread is arranged on the cap, the connecting external thread is screwed into the locking internal thread, the connecting external thread section of the cap is installed in the connecting sleeve, and the end of the connecting external thread section of the cap abuts against the end of the positioning nut. According to the utility model, the pressure head is convenient and fast to disassemble and assemble; and when the pressure head is subjected to unbalance loading during operation, the overall bending resistance limit is larger.

Description

Technical Field

[0001] The utility model relates to a structure for connecting a pressure head with the end of a piston rod of an oil cylinder, belonging to the field of mechanical equipment. Background Art

[0002] An oil cylinder is a commonly used driving device. When the oil cylinder is driving, especially when it is used as an extrusion element, a pressure head is often installed at the end of the piston rod, and the pressure head is used to extrude the target product; when the pressure head is worn, the pressure head can be conveniently replaced to resume production.

[0003] In order to facilitate the replacement of the pressure head, the applicant previously applied for and disclosed a connection structure between an oil cylinder and a pressure head with Chinese Patent Publication No. CN219139529U. A snap ring is installed on the protruding head of the piston rod, and the snap ring is tightened by a union nut to fix the pressure head on the protruding head.

[0004] However, for the above structure, a snap ring groove needs to be machined on the protruding head of the piston rod, resulting in a relatively small bending resistance limit at the snap ring groove of the protruding head; when the pressure head generates a bias pressure during operation, a bias pressure will be generated on the piston rod, which is likely to cause cracks at the snap ring groove, and ultimately easily lead to accidental fracture of the piston rod.

[0005] Therefore, for the use situation with bias pressure, it is necessary to further improve the connection structure between the pressure head and the piston rod of the oil cylinder. Summary of the Utility Model

[0006] The purpose of the utility model is to provide a connection structure between a pressure head and an oil cylinder, which optimizes the snap connection structure between the snap ring and the protruding head into a threaded connection, uses a positioning nut instead of the snap ring, thereby avoiding the grooving of the protruding head, and further avoiding the local stress concentration at the end of the piston rod. Therefore, even under the condition of bias pressure, it will not cause local cracking of the protruding head, improving the service life of the equipment, and at the same time retaining the quick replacement characteristic of the pressure head.

[0007] To achieve the above-mentioned utility model purpose, the utility model provides a connection structure between a pressure head and an oil cylinder, including an oil cylinder, a piston rod is arranged in the oil cylinder, the end of the piston rod is a protruding head, and a pressure head is installed on the protruding head; a connection sleeve is arranged at the rear of the pressure head;

[0008] The pressure head is fixed on the protruding head through the connection sleeve in combination with a positioning nut and a union nut;

[0009] At the middle part of the protruding head, on the side close to the cylinder body of the oil cylinder after the pressure head is installed, there is an external thread;

[0010] The positioning nut is provided with an internal thread matching the external thread, and the external thread and the internal thread form a threaded connection. The positioning nut is fixed at the middle part of the protruding head; the positioning nut does not contact the pressure head;

[0011] The interior of the connecting sleeve is provided with a locking internal thread; the connecting part between the connecting sleeve and the pressing head forms a receiving cavity for receiving the positioning nut;

[0012] The union nut is located on the piston rod between the positioning nut and the cylinder block of the oil cylinder;

[0013] The union nut is provided with an external connecting thread, the external connecting thread is screwed into the locking internal thread, the connecting external thread section of the union nut is installed into the connecting sleeve, and the end of the connecting external thread section of the union nut abuts against the end of the positioning nut.

[0014] As a further improvement of the present utility model, the thread connection between the internal thread of the positioning nut and the external thread of the protruding head is a fine thread connection.

[0015] As a further improvement of the present utility model, a thread locking adhesive is provided between the internal thread of the positioning nut and the external thread of the protruding head.

[0016] As a further improvement of the present utility model, the inner diameter of the connecting external thread section of the union nut is smaller than the outer diameter of the positioning nut.

[0017] As a further improvement of the present utility model, the inner diameter of the union nut is larger than the major diameter of the external thread on the protruding head.

[0018] As a further improvement of the present utility model, the minor diameter of the locking internal thread of the connecting sleeve is larger than the outer diameter of the positioning nut.

[0019] As a further improvement of the present utility model, the upper part of the union nut is provided with a clamping part.

[0020] Furthermore, a relief groove is provided between the clamping part of the union nut and the connecting external thread.

[0021] As a further improvement of the present utility model, a positioning hole is provided in the middle of the pressing head, and the end of the protruding head is inserted into the positioning hole;

[0022] There is an interference fit between the protruding head and the positioning hole;

[0023] The bottom of the positioning hole is in surface contact with the end of the protruding head.

[0024] As a further improvement of the present utility model, the connecting sleeve is a separate ring, and the connecting sleeve is fixed to the rear of the pressing head by welding.

[0025] As a further improvement of the present utility model, the connecting sleeve and the pressing head are integrally formed parts.

[0026] When the connection structure between the pressing head of the present utility model and the oil cylinder is used, first put the union nut on the protruding head of the piston rod of the oil cylinder, with the clamping part of the union nut facing the cylinder block of the oil cylinder and the connecting external thread facing outwards; then, take out the positioning nut and screw it onto the external thread of the protruding head. At this time, the union nut is restricted on the piston rod between the positioning nut and the cylinder block of the oil cylinder.

[0027] Then install the pressure head, insert the protruding head into the positioning hole, and the locking internal thread of the connecting sleeve passes over the positioning nut; then, screw the union nut into the locking internal thread of the connecting sleeve until the end of the union nut abuts against the union nut to achieve locking. That is, the installation of the pressure head at the end of the piston rod of the oil cylinder is completed.

[0028] When replacing the pressure head, it is only necessary to loosen the union nut and screw the union nut completely out of the connecting sleeve, then the pressure head can be removed and a new pressure head can be installed.

[0029] For the connection structure between the pressure head and the oil cylinder of the present utility model, when the pressure head is subjected to eccentric load during operation, since the piston rod of the oil cylinder in this structure has good integrity and no grooves, the overall bending resistance limit is larger, providing better protection for the piston rod of the oil cylinder. Furthermore, the service life of the oil cylinder is longer. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of the overall structure of the connection structure between the pressure head and the oil cylinder of the present utility model;

[0031] Figure 2 is a partially enlarged cross-sectional view of the connection structure between the pressure head and the oil cylinder of the present utility model;

[0032] Figure 3 is a schematic diagram of the internal structure of the connection structure between the pressure head and the oil cylinder of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The following further describes in detail the specific embodiments of the present utility model with reference to the accompanying drawings.

[0034] The connection structure between the pressure head and the oil cylinder of the present utility model, as Figures 1 - 3 shown, is the same as that disclosed in the connection structure between the oil cylinder and the pressure head with Chinese Patent Publication No. CN219139529U, and includes an oil cylinder 1. A piston rod is provided inside the oil cylinder 1, and the end of the piston rod is a protruding head 11. A pressure head 2 is installed on the protruding head; a connecting sleeve 3 is provided at the rear of the pressure head 2, and the pressure head 2 is fixed on the protruding head 11 through the connecting sleeve 3 in combination with a positioning nut 4 and a union nut 5.

[0035] A positioning hole 21 is provided in the middle of the pressure head 2, and the end of the protruding head 11 is inserted into the positioning hole 21, and the outer diameter of the protruding head 11 matches the outer diameter of the positioning hole 21, generally using an interference fit, so that the pressure head 2 can be reliably installed on the protruding head 11 through the positioning hole 21 without obvious gaps and no radial displacement will occur.

[0036] After the pressure head 2 is installed in place, the bottom 22 of the positioning hole 21 is in contact with the end 12 of the protruding head 11 to form a surface contact for transmitting the pressure of the oil cylinder 1.

[0037] A connecting sleeve 3 is provided at the rear of the indenter 2; the connecting sleeve 3 is preferably a separate ring, and then fixed to the rear of the indenter 2 by welding, thereby saving manufacturing costs; of course, it can also be as Figure 3 shown, the indenter 2 and the connecting sleeve 3 are integrally formed by machining from a whole piece of material. The end of the indenter 2 can be locally quenched to increase the surface hardness, so as to be more wear-resistant and durable.

[0038] The improvement of the connection structure between the indenter of the present utility model and the oil cylinder is that a positioning nut 4 is provided in the middle of the protruding head 11; as Figure 2 shown, specifically, on the inner side (above the illustration) of the positioning hole 21 of the protruding head 11 where the indenter 2 is installed, an external thread 13 is provided, which is matched with the internal thread 41 of the positioning nut 4, and the external thread 13 and the internal thread 41 form a threaded connection, preferably a fine thread, so that the positioning nut 4 can be installed on the protruding head 11, and the positioning nut 4 does not contact the indenter 2.

[0039] At the same time, a locking internal thread 31 is provided inside the connecting sleeve 3; the connection part between the connecting sleeve 3 and the indenter 2 forms a receiving cavity 32 for receiving the positioning nut 4, and no internal thread needs to be provided at this part.

[0040] Therefore, the union nut 5 is inserted into the connecting sleeve 3 from the upper part. The union nut 5 is provided with an external connection thread 51, and the external connection thread 51 is screwed into the locking internal thread 31, so as to install the union nut 5 on the connecting sleeve 3; further, the inner diameter of the bottom end of the union nut 5 is smaller than the outer diameter of the positioning nut 4. As the union nut 5 is screwed into the connecting sleeve 3, the bottom end of the union nut 5 abuts against the top end of the positioning nut 4, and an extrusion connection is formed between the union nut 5 and the positioning nut 4, which realizes axial positioning and locking and also realizes anti-loosening by extrusion.

[0041] A clamping part 52 is provided on the upper part of the union nut 5 for connecting with a tightening tool such as a wrench; a relief groove 53 can be provided between the clamping part 52 and the external connection thread 51.

[0042] The inner diameter of the union nut 5 is larger than the major diameter of the external thread 13 on the protruding head 11, so the union nut 5 can be sleeved from the end of the protruding head 11 and then pass over the external thread 13 part.

[0043] The minor diameter of the locking internal thread 31 of the connecting sleeve 3 is larger than the outer diameter of the positioning nut 4, so the connecting sleeve 3 can be sleeved from the end of the protruding head 11 and then partially pass over the positioning nut 4 to accommodate the positioning nut 4 in the receiving cavity 32.

[0044] When the connection structure between the indenter and the oil cylinder of the present utility model is in use, first, the union nut 5 is sleeved on the protruding head 11 of the piston rod of the oil cylinder 1, with the clamping portion 52 of the union nut 5 facing the cylinder block of the oil cylinder 1 and the connecting external thread 51 facing outwards; then, the positioning nut 4 is taken out and screwed onto the external thread 13 of the protruding head 11, and at this time, the union nut 5 is restricted on the piston rod between the positioning nut 4 and the cylinder block of the oil cylinder 1; to improve the connection reliability of the positioning nut 4, thread locking glue can be applied between the internal thread 41 of the positioning nut 4 and the external thread 13 of the protruding head 11 to lock the positioning nut 4 firmly on the protruding head 11; when it is necessary to disassemble the positioning nut 4 and replace the union nut 5, it can be disassembled after melting the thread locking glue by heating or other means; the union nut 5 and the positioning nut 4 are pre-installed on the protruding head 11 of the piston rod.

[0045] Then, the indenter 2 is installed, so that the protruding head 11 is inserted into the positioning hole 21, the bottom 22 of the positioning hole 21 contacts the end 12 of the protruding head 11, and the locking internal thread 31 of the connecting sleeve 3 passes over the positioning nut 4; then, the union nut 5 is screwed into the locking internal thread 31 of the connecting sleeve 3 until the end of the union nut 5 abuts against the union nut 3 to achieve locking.

[0046] When replacing the indenter 2, it is only necessary to loosen the union nut 5 and completely screw the union nut 5 out of the connecting sleeve 3, then the indenter 2 can be removed and a new indenter 2 can be replaced.

[0047] For the connection structure between the indenter and the oil cylinder of the present utility model, when the indenter 2 is subjected to eccentric load during operation, since the piston rod of the oil cylinder in this structure has good integrity and no grooves, the overall bending resistance limit is greater, providing better protection for the oil cylinder. Furthermore, the service life of the oil cylinder 1 is longer.

[0048] The preferred embodiments of the present utility model have been specifically described above, but the present utility model is not limited to the described embodiments. Those skilled in the art can make various equivalent variations or substitutions without departing from the spirit of the present utility model, and these equivalent variations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. Connection structure between indenter and oil cylinder, including an oil cylinder with a piston rod disposed therein. The end of the piston rod is an extended head, and an indenter is mounted on the extended head; a connecting sleeve is provided at the rear of the indenter. It is characterized in that The indenter is fixed on the extended head through the connecting sleeve in combination with a positioning nut and a union nut. At the middle of the extended head, on the side close to the cylinder body of the oil cylinder after the indenter is mounted, there is an external thread. The positioning nut is provided with an internal thread matching the external thread. The external thread and the internal thread form a threaded connection, and the positioning nut is fixed at the middle of the extended head; the positioning nut does not contact the indenter. The inside of the connecting sleeve is provided with a locking internal thread; the connection part between the connecting sleeve and the indenter forms a receiving cavity for receiving the positioning nut. The union nut is located on the piston rod between the positioning nut and the cylinder body of the oil cylinder. The union nut is provided with a connecting external thread. The connecting external thread is screwed into the locking internal thread. The connecting external thread section of the union nut is installed into the connecting sleeve, and the end of the connecting external thread section of the union nut abuts against the end of the positioning nut.

2. The connecting structure of the indenter and the oil cylinder according to claim 1, wherein The threaded connection between the internal thread of the positioning nut and the external thread of the extended head is a fine pitch thread connection.

3. The connecting structure between the indenter and the oil cylinder according to claim 1, characterized in that, There is a thread locking adhesive between the internal thread of the positioning nut and the external thread of the extended head.

4. The connecting structure between the indenter and the oil cylinder according to claim 1, characterized in that, The inner diameter of the connecting external thread section of the union nut is smaller than the outer diameter of the positioning nut.

5. The connecting structure of the indenter and the oil cylinder according to claim 1, characterized in that, The inner diameter of the union nut is larger than the major diameter of the external thread on the extended head.

6. The connecting structure between the indenter and the oil cylinder according to claim 1, characterized in that, The minor diameter of the locking internal thread of the connecting sleeve is larger than the outer diameter of the positioning nut.

7. The connecting structure between the indenter and the oil cylinder according to claim 1, characterized in that The upper part of the union nut is provided with a clamping portion.

8. The connecting structure between the indenter and the oil cylinder according to claim 7, characterized in that, There is a relief groove between the clamping portion of the union nut and the connecting external thread.

9. The connecting structure between the indenter and the oil cylinder according to claim 1, characterized in that, A positioning hole is provided in the middle of the indenter, and the end of the extended head is inserted into the positioning hole. There is an interference fit between the extended head and the positioning hole. There is a surface contact between the bottom of the positioning hole and the end of the extended head.

10. The connecting structure between the indenter and the oil cylinder according to claim 1, characterized in that, The connecting sleeve is a separate ring, and the connecting sleeve is welded and fixed at the rear of the indenter.

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