Pneumatic internal expansion type tool for machine tool

Abstract

The utility model relates to a pneumatic internal expansion type tool for a machine tool, which solves the technical problems that under the condition that a chuck and a core shaft on the existing numerical control machine tool process pipe fittings in batches for a long time, the core shaft is abraded, so that the axes of the pipe fittings and the axis of the core shaft cannot be overlapped, and the cost of replacing the core shaft is too high, and comprises a left chuck and a tailstock connecting device, the left chuck comprises a left disc, a left air cavity base, a left gland, a left sliding disc, a spring, a left tensioning sleeve connecting shaft, a first pull rod, a first nut seat, a bolt and a left tensioning sleeve. The tailstock connecting device comprises a supporting base, a connecting shaft, a needle bearing, a tail locating sleeve, a self-aligning ball bearing, an elastic check ring, a bearing spacer sleeve, a right air cavity base, a right gland, a right sliding disc, a second nut base, a right tensioning sleeve connecting shaft, a second pull rod and a right tensioning sleeve. The device is widely used for machining pipe fittings on a machine tool.

Description

Technical Field

[0001] The utility model relates to the technical field of pipe fitting processing, in particular to a pneumatic internal expansion tooling for a machine tool. Background Art

[0002] During the processing of pipe fittings, the chuck of the CNC machine tool fixes one end of the pipe fitting by clamping or supporting it, and the mandrel is installed on the rear tailstock of the machine tool. The front end of the mandrel supports the other end of the pipe fitting, and then the processing is carried out. However, under long-term batch processing, the mandrel will wear, resulting in the mandrel's accuracy not meeting the requirements, which in turn leads to low coaxiality between the pipe fitting and the mandrel, and it cannot be guaranteed that the axis of the pipe fitting coincides with the axis of the mandrel, which ultimately causes the size of the pipe fitting to fail to meet the design requirements. If a new mandrel is replaced, the processing cost will increase. Summary of the invention

[0003] The utility model provides a pneumatic internal expansion tool for a machine tool in order to solve the technical problems that when the chuck and the mandrel on the existing CNC machine tool are used for long-term batch processing of pipe fittings, the mandrel is worn so that the axis of the pipe fitting and the axis of the mandrel cannot be coincident, and the cost of replacing the mandrel is too high.

[0004] The utility model provides a pneumatic internal expansion tooling for a machine tool, comprising a left chuck, a tailstock connecting device and an air pipe;

[0005] The left chuck comprises a left circular disc, a left air cavity base, a left pressure cover, a left sliding disc, a spring, a left tension sleeve connecting shaft, a first pull rod, a first nut seat, a bolt and a left tension sleeve. The left air cavity base is located between the left circular disc and the left pressure cover. A plurality of screws are first passed through the left pressure cover and then through the left air cavity base, and then connected with the threaded holes on the left circular disc. The air pipe passes through the left circular disc, and the end of the air pipe is fixedly connected to the left end of the left sliding disc. The left air cavity base is provided with a chamber, and the left sliding disc is located in the chamber. The left air cavity base A central through hole is provided, the left end of the left sliding disk is located in the central through hole of the air cavity base, the left end of the left sliding disk is slidably connected to the central through hole of the air cavity base, a sealing ring is provided between the left end of the left sliding disk and the inner wall of the central through hole of the air cavity base; a sealing ring is connected between the periphery of the left sliding disk and the side wall of the chamber, and the left sliding disk can slide in the chamber; a side vent hole and a circumferential arc groove are provided at the end of the air pipe, the circumferential arc groove is connected to the side vent hole, and the side vent hole is connected to the air pipe The channel is connected, and a plurality of air holes are provided at the left end of the left sliding disk, and the plurality of air holes are connected with the side air holes, and the plurality of air holes are connected with the chamber; a spring positioning groove is provided on the inner side surface of the left pressure cover, and the spring is located in the spring positioning groove, and the right end surface of the left sliding disk contacts the spring, and the number of springs is multiple; the left tensioning sleeve connecting shaft is fixedly connected to the outer side surface of the left pressure cover by screws, and the left tensioning sleeve connecting shaft is provided with a guide center through hole, and the first pull rod passes through the guide center through hole of the left tensioning sleeve connecting shaft and can slide; the left tensioning sleeve is sleeved on the right end of the first pull rod and the right end of the left tensioning sleeve connecting shaft; the first nut seat is fixedly connected to the central part of the right end surface of the left sliding disk by screws, and the left end of the first pull rod is provided with an external thread, and the external thread of the left end of the first pull rod is connected with the internal thread on the first nut seat; an annular clamping boss is provided on the outer edge of the end surface of the left disc, and a plurality of bolts pass through the left disc from the inside to the outside, and the plurality of bolts are evenly distributed along the circumferential direction of the left disc, and the thread head of each bolt is exposed outside;

[0006] The tailstock connecting device includes a supporting seat, a connecting shaft, a needle roller bearing, a tail locating sleeve, a self-aligning ball bearing, an elastic retaining ring, a bearing retaining sleeve, a right air chamber base, a right pressure cover, a right sliding disk, a second nut seat, a right tensioning sleeve connecting shaft, a second pull rod and a right tensioning sleeve. The supporting seat is provided with an axial center through hole, the connecting shaft is located in the axial center through hole, the rear end of the connecting shaft is rotatably connected to the rear end of the supporting seat through a needle roller bearing, and the tail locating sleeve is connected to the rear end of the supporting seat; a bearing chamber is provided at the front end of the supporting seat, the self-aligning ball bearing is located in the bearing chamber, the front part of the connecting shaft is connected to the inner ring of the self-aligning ball bearing, and the elastic retaining ring is provided in the bearing chamber. The elastic retaining ring is located at the bottom of the bearing chamber at the front end of the support seat, the self-aligning ball bearing presses down the elastic retaining ring, the bearing retaining sleeve is sleeved on the front part of the connecting shaft, and the bearing retaining sleeve is connected to the opening of the bearing chamber at the front end of the support seat; two sealing rings are connected between the connecting shaft and the support seat, and the front end of the connecting shaft is a disc part, which is fixedly connected to the right air cavity base by multiple screws; the support seat is provided with a compressed air inlet and outlet channel, the connecting shaft is provided with a circumferential arc groove, a side air hole and an axial air hole, the side air hole is connected to the circumferential arc groove, the axial air hole is connected to the side air hole, and the compressed air inlet and outlet channel is connected to the side air hole ; Two sealing rings between the connecting shaft and the supporting seat are located on both sides of the side air holes; the right air cavity base is provided with a chamber, and a guide hole is provided at the central part of the right air cavity base, and the guide hole is connected with the axial air hole of the connecting shaft; the right pressure cover is fixedly connected with the right air cavity base by multiple screws, the right sliding disk is located in the chamber of the right air cavity base, and a sealing ring is connected between the periphery of the right sliding disk and the side wall of the chamber of the right air cavity base, the inner side of the right pressure cover is provided with a spring positioning groove, and a spring is provided in the spring positioning groove of the right pressure cover, the left end surface of the right sliding disk is in contact with the spring on the right pressure cover, and multiple springs are provided; the right sliding The right end of the disk is provided with an axial air inlet hole and a side air inlet hole which are connected together. There are multiple side air inlet holes, and the side air inlet holes are connected to the chamber of the right air cavity base; the right end of the right sliding disk is located in the guide hole of the right air cavity base 710 and can slide; the second nut seat is fixedly connected to the middle part of the left end surface of the right sliding disk by screws; the right tensioning sleeve connecting shaft is fixedly connected to the right pressure cover by multiple screws; the right tensioning sleeve connecting shaft is provided with a guide through hole, the second pull rod passes through the guide through hole of the right tensioning sleeve connecting shaft and can slide, and the right tensioning sleeve is sleeved on the left end portion of the second pull rod and the left end of the right tensioning sleeve connecting shaft.

[0007] Preferably, the end of the air pipe is inserted into the left end of the left sliding plate and fixed in an interference fit manner.

[0008] Preferably, the pneumatic internal expansion tooling for a machine tool further comprises a rotary joint, which is connected to the air pipe.

[0009] Preferably, three guide pins are fixedly connected to the end surface of the left air cavity base, and three guide holes are provided on the end surface of the left sliding disk. The guide holes correspond to the guide pins, and the ends of the guide pins are located in the guide holes.

[0010] Preferably, a fine-tuning screw is connected to the left gland, and the end of the fine-tuning screw abuts against the outer side of the connecting shaft of the left tension sleeve.

[0011] Preferably, the number of the fine-tuning screws is three or four, and the three or four fine-tuning screws are evenly distributed along the circumferential direction.

[0012] Preferably, the right gland is connected with a fine-tuning screw, and the end of the fine-tuning screw abuts against the outer side of the right tension sleeve connecting shaft.

[0013] Preferably, the number of the fine-tuning screws is three or four.

[0014] The utility model has the beneficial effects of ensuring coaxiality after long-term use, saving costs, and not requiring the replacement of the mandrel as in the prior art. The processing quality of the pipe products is ensured. The operation is simple and fast, which is conducive to improving the processing efficiency. The stability is good and the reliability is high. The long-term use does not easily cause damage and does not require replacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the front view of the pneumatic internal expansion tooling for machine tools;

[0016] Figure 2 yes Figure 1 Sectional view in the AA direction;

[0017] Figure 3 yes Figure 2 In the structure shown, a partial structural diagram of the left chuck;

[0018] Figure 4 yes Figure 2 A partial structural diagram of the air pipe connected to the left sliding plate of the left chuck in the structure shown;

[0019] Figure 5 yes Figure 2 A partial structural diagram of the tailstock connection device in the structure shown;

[0020] Figure 6 yes Figure 2 In the structure shown, a partial structural diagram of the connection between the connecting shaft and the supporting seat;

[0021] Figure 7 It is a structural schematic diagram of a fine-tuning screw connected to the right pressure cover of the tailstock connecting device.

[0022] Explanation of symbols in the figure:

[0023] 100. Left chuck, 101. Left disc, 101-1. Annular clamping boss, 102. Left air chamber base, 102-1. Chamber, 103. Screw, 104. Left gland, 105. Left sliding disc, 105-1. Air hole, 106. Sealing ring, 107. Sealing ring, 108. Spring, 109. Left tension sleeve connecting shaft, 110. First pull rod, 111. First nut seat, 112. Screw, 113. Screw, 114. Bolt, 115. Guide pin shaft, 116. Fine adjustment screw, 117. Left tension sleeve; 500. Rotary joint, 600. Air pipe, 601. Channel, 602. Side vent, 603. Circumferential arc groove, 700. Tailstock connecting device, 701. Support seat, 701-1. Compressed air inlet and outlet channel, 702 .Connecting shaft, 702-1. Side air hole, 702-2. Axial air hole, 702-3. Circumferential arc groove, 703. Needle roller bearing, 704. Tail positioning sleeve, 705. Self-aligning ball bearing, 706. Elastic retaining ring, 707. Bearing retaining sleeve, 708. Sealing ring, 709. Screw, 710. Right air chamber base, 710-1. Chamber, 710-2. Guide hole, 711. Right pressure cover, 712. Screw, 713. Right sliding plate, 713-1. Axial air inlet hole, 713-2. Side air inlet hole, 714. Spring, 715. Sealing ring, 716. Second nut seat, 717. Screw, 718. Right tension sleeve connecting shaft, 719. Second pull rod, 720. Screw, 721. Right tension sleeve, 722. Fine-tuning screw; 300. Pipe fittings. DETAILED DESCRIPTION

[0024] like Figure 1-6 As shown, the pneumatic internal expansion tooling for a machine tool comprises a left chuck 100 , a tailstock connecting device 700 and an air pipe 600 .

[0025] The left chuck 100 includes a left disc 101, a left air cavity base 102, a screw 103, a left pressure cover 104, a left sliding disc 105, a sealing ring 106, a sealing ring 107, a spring 108, a left tension sleeve connecting shaft 109, a first pull rod 110, a first nut seat 111, a screw 112, a screw 113, a bolt 114, and a left tension sleeve 117. The left air cavity base 102 is located between the left disc 101 and the left pressure cover 104. A plurality of screws 103 first pass through the left pressure cover 104 and then through the left air cavity base 102, and then are connected with the threaded holes on the left disc 101, so as to realize the fixed assembly of the left disc 101, the left air cavity base 102, and the left pressure cover 104 together. The air pipe 600 passes through the left disc 101, and the end of the air pipe 600 is inserted into the left end of the left sliding disc 105 to be interference fit. The left air cavity base 102 is fixed in the same manner as the left air cavity base 102, the left sliding disk 105 is located in the chamber 102-1, the left air cavity base 102 is provided with a central through hole, the left end of the left sliding disk 105 is located in the central through hole of the air cavity base 102, the left end of the left sliding disk 105 is slidably connected to the central through hole of the air cavity base 102, and a sealing ring 106 is provided between the left end of the left sliding disk 105 and the inner wall of the central through hole of the air cavity base 102; when the air cavity base 102 is stationary, the left end of the left sliding disk 105 can slide in the central through hole of the air cavity base 102, and since the end of the air pipe 600 is fixedly connected to the left end of the left sliding disk 105, the left sliding disk 105 drives the air pipe 600 to move, and the other end of the air pipe 600 arranged in the rotary joint 500 slides with the rotary joint 500 as a reference. The sealing ring 107 is connected between the periphery of the left sliding disk 105 and the side wall of the chamber 102-1, and the left sliding disk 105 can slide in the chamber 102-1. The end of the air pipe 600 is provided with a side vent 602 and a circumferential arc groove 603, the circumferential arc groove 603 is connected to the side vent 602, the side vent 602 is connected to the channel 601, and the left end of the left sliding disk 105 is provided with four air holes 105-1, each of which is connected to the side vent 602, and the air hole 105-1 is connected to the chamber 102-1. The inner side surface of the left gland 104 is provided with a spring positioning groove, and the spring 108 is located in the spring positioning groove. The right end surface of the left sliding disk 105 contacts the spring 108, that is, the spring 108 is provided between the right end surface of the left sliding disk 105 and the left gland 104, and the number of the springs 108 is multiple (for example, it can be three, four or six).The left tensioning sleeve connecting shaft 109 is fixedly connected to the outer side surface of the left pressure cover 104 by means of screws 113. The left tensioning sleeve connecting shaft 109 is provided with a center through hole. The first pull rod 110 passes through the guide center through hole of the left tensioning sleeve connecting shaft 109. The first pull rod 110 can slide in the guide center through hole. The left tensioning sleeve 117 is sleeved on the right end of the first pull rod 110. The left tensioning sleeve 117 is also sleeved on the right end of the left tensioning sleeve connecting shaft 109. The matching structure of the left tensioning sleeve 117 and the right end of the first pull rod 110 and the right end of the left tensioning sleeve connecting shaft 109 is a conventional structure in the prior art. The first nut seat 111 is fixedly installed on the central part of the right end surface of the left sliding disk 105 by means of a screw 112. The left end of the first pull rod 110 is provided with an external thread, and the external thread on the left end of the first pull rod 110 is connected to the internal thread on the first nut seat 111, thereby fixing the left end of the first pull rod 110 to the central part of the right end surface of the left sliding disk 105. When the left chuck 100 is working, the rotary joint 500 is connected to the air pipe 600 (the air pipe 600 can rotate radially with the rotary joint 500 as a reference, and can also slide axially with the rotary joint 500 as a reference), and compressed air is input. The compressed air enters the channel 601 of the air pipe 600 from the rotary joint 500, and then enters the chamber 102-1 through the air hole 105-1. Then, the compressed air in the chamber 102-1 pushes the left sliding disk 105 to move right, and the left sliding disk 105 moves right with the first pull rod 110, the spring 108 is compressed, and the first pull rod 110 moves to the right to make the left tensioning sleeve 117 in a relaxed state (such as. Figure 2 The pressure is released, the force of the compressed air disappears, and the left sliding plate 105 moves to the left to return to its original position under the elastic force of the spring 108, and the first pull rod 110 moves to the left accordingly. At this time, the left tensioning sleeve is in a tensioned state.

[0026] The outer edge of the end surface of the left disk 101 is provided with an annular clamping boss 101-1, which is used to cooperate with the flange on the main shaft of the machine tool. Six bolts 114 pass through the left disk 101 from the inside to the outside, and the six bolts 114 are evenly distributed along the circumference of the left disk 101. The threaded heads of the bolts 114 are exposed outside.

[0027] The tailstock connecting device 700 includes a support seat 701, a connecting shaft 702, a needle bearing 703, a tail positioning sleeve 704, a self-aligning ball bearing 705, an elastic retaining ring 706, a bearing retaining sleeve 707, a sealing ring 708, a screw 709, a right air chamber base 710, a right pressure cover 711, a screw 712, a right sliding disk 713, a spring 714, a sealing ring 715, a second nut seat 716, a screw 717, a right tensioning sleeve connecting shaft 718, a second pull rod 719, a screw 720, and a right tensioning sleeve 721. The support seat 701 is provided with an axial center through hole, and the connecting shaft 702 is located in the axial center through hole. The rear end of the connecting shaft 702 is rotatably connected to the rear end of the support seat 701 through the needle bearing 703, and the tail positioning sleeve 704 is connected to the rear end of the support seat 701. The tail positioning sleeve 704 is used to position the needle bearing 703 and the rear end of the connecting shaft 702. The front end of the support seat 701 is provided with a bearing chamber, in which the self-aligning ball bearing 705 is located, the front part of the connecting shaft 702 is connected to the inner ring of the self-aligning ball bearing 705, the elastic retaining ring 706 is located at the bottom of the bearing chamber at the front end of the support seat 701, the self-aligning ball bearing 705 presses down the elastic retaining ring 706, the bearing stopper sleeve 707 is sleeved on the front part of the connecting shaft 702, the bearing stopper sleeve 707 is connected to the opening of the bearing chamber at the front end of the support seat 701, and the bearing stopper sleeve 707 presses down the outer ring of the self-aligning ball bearing 705, that is, the front part of the connecting shaft 702 is rotatably connected to the front part of the support seat 701 through the self-aligning ball bearing 705, and the entire connecting shaft 702 can rotate. Two sealing rings 708 are connected between the connecting shaft 702 and the support seat 701. The front end of the connecting shaft 702 is a disc portion, and a plurality of screws 709 pass through the disc portion. The support seat 701 is provided with a compressed air inlet and outlet channel 701-1, and the connecting shaft 702 is provided with a circumferential arc groove 702-3, a side air hole 702-1, and an axial air hole 702-2. The side air hole 702-1 is connected to the circumferential arc groove 702-3, the axial air hole 702-2 is connected to the side air hole 702-1, and the compressed air inlet and outlet channel 701-1 is connected to the side air hole 702-1. Two sealing rings 708 are located on both sides of the side air hole 702-1. Regardless of how the connecting shaft 702 and the support seat 701 rotate relative to each other, external compressed air can enter the axial air hole 702-2 through the compressed air inlet and outlet channel 701-1.The screw 709 is connected with the threaded hole on the rear end face of the right air cavity base 710, so as to fix the right air cavity base 710 and the front end disc part of the connecting shaft 702 together; the right air cavity base 710 is provided with a chamber 710-1, and the central part of the right air cavity base 710 is provided with a guide hole 710-2, and the guide hole 710-2 is connected with the axial air hole 702-2; a plurality of screws 712 are passed through the right gland 711 and connected with the threaded hole on the front end face of the right air cavity base 710, Thus, the right gland 711 is fixedly connected to the right air chamber base 710, the right sliding plate 713 is located in the chamber 710-1 of the right air chamber base 710, a sealing ring 715 is connected between the periphery of the right sliding plate 713 and the side wall of the chamber 710-1, a spring positioning groove is provided on the inner side of the right gland 711, a spring 714 is placed in the spring positioning groove, the left end face of the right sliding plate 713 is in contact with the spring 714, and a plurality of springs 714 (for example, three or four springs 714) are provided. or six); the right end of the right sliding disk 713 is provided with an axial air inlet hole 713-1 and a side air inlet hole 713-2, the side air inlet hole 713-2 is communicated with the axial air inlet hole 713-1, there are multiple side air inlet holes 713-2 (four are shown in the figure for example only), and the side air inlet hole 713-2 is communicated with the chamber 710-1; the right end of the right sliding disk 713 is located in the guide hole 710-2, and the right end of the right sliding disk 713 can be in the guide hole 710 -2; the second nut seat 716 is fixedly connected to the middle of the left end surface of the right sliding disk 713 by screws 717, the right tension sleeve connecting shaft 718 is fixedly connected to the right gland 711 by multiple screws 720, the second tie rod 719 passes through the guide through hole of the right tension sleeve connecting shaft 718, the second tie rod 719 can slide in the guide through hole, the right tension sleeve 721 is sleeved on the left end of the second tie rod 719, and the right tension sleeve 721 is sleeved on the left end of the right tension sleeve connecting shaft 718. The matching structure of the right tension sleeve 721, the second tie rod 719 and the left end of the right tension sleeve connecting shaft 718 is a conventional structure in the prior art. When the tailstock connection device 700 is working, compressed air is input from the compressed air inlet and outlet channel 701-1 of the support seat 701, and then the compressed air passes through the side air hole 702-1 and then the axial air hole 702-2, and then passes through the axial air inlet hole 713-1 and the side air inlet hole 713-2 in sequence to enter the chamber 710-1. The compressed air in the chamber 710-1 pushes the right sliding plate 713 to move leftward, and the right sliding plate 713 moves leftward with the second pull rod 719, and the spring 714 is compressed. Figure 2 The spring 714 is shown in a compressed state), the second pull rod 719 moves to the left to make the right tensioning sleeve 721 in a relaxed state, at this time the pressure is released, the force of the compressed air disappears, and under the elastic force of the spring 714, the right sliding disk 713 moves to the right to return to its original position, and the second pull rod 719 moves to the right accordingly, and at this time the right tensioning sleeve 721 is in a tensioned state.

[0028] The following describes the use of the above-mentioned pneumatic internal expansion tooling for machine tools:

[0029] First, the left disc 101 of the left chuck 100 is docked with the flange on the machine tool spindle, the annular clamping boss 101-1 is matched with the flange, the threaded heads of the six bolts 114 pass through the connection holes on the flange, and nuts are connected to the threaded heads of the bolts 114 to tighten, so that the left disc 101 is fixedly connected to the flange on the machine tool spindle. The air pipe 600 is located in the central through hole of the machine tool spindle.

[0030] Secondly, the support base 701 of the tailstock connecting device 700 is fixedly installed on the rear tailstock of the machine tool.

[0031] Then, the rotary joint 500 is connected to the air pipe 600, and a compressed air hose is used to connect the rotary joint 500. The air pipe 600 is ventilated through the compressed air hose, and the left sliding plate 105 moves to the right, and the left sliding plate 105 moves to the right with the first pull rod 110, the spring 108 is compressed, and the first pull rod 110 moves to the right to make the left tension sleeve 117 in a relaxed state (such as Figure 2 status shown).

[0032] Then, prepare the pipe 300 to be processed, and put the left end of the pipe 300 on the left tensioning sleeve 117. Next, release the pressure, and the force of the compressed air disappears. Under the elastic force of the spring 108, the left sliding disk 105 moves to the left and returns to its original position, and the first pull rod 110 moves to the left accordingly. At this time, the left tensioning sleeve is in a tensioned state and then supports the left end of the pipe 300, so that the left end of the pipe 300 is fixed.

[0033] Then, compressed air is input to the tailstock connecting device 700 through the compressed air inlet and outlet channel 701-1, the right sliding plate 713 moves to the left, and the right sliding plate 713 moves to the left with the second pull rod 719, the spring 714 is compressed, and the second pull rod 719 moves to the left to relax the right tension sleeve 721.

[0034] Then, the rear tailstock of the machine tool is moved to insert the right tension sleeve 721 into the right end of the pipe fitting 300, and then the tailstock connection device 700 is depressurized, the force of the compressed air disappears, and the right tension sleeve 721 is in a tensioned state, thereby supporting the right end of the pipe fitting 300 and fixing the right end of the pipe fitting 300. At this point, the pipe fitting 300 is positioned.

[0035] Finally, the machine tool is started, the left chuck 100 rotates, the right air chamber base 710 and the connecting shaft 702 of the tailstock connecting device 700 rotate, the pipe 300 rotates, and the pipe 300 is processed by a tool.

[0036] It should be noted that after compressed air is passed through the left chuck 100 and the tailstock connecting device 700, the left end of the pipe fitting 300 is sleeved on the left tensioning sleeve 117, and the right end of the pipe fitting 300 is sleeved on the right tensioning sleeve 721, and then the left chuck 100 and the tailstock connecting device 700 are depressurized at the same time, and the left tensioning sleeve 117 and the right tensioning sleeve 721 simultaneously support the pipe fitting 300.

[0037] In order to make the left sliding plate 105 move more stably, three guide pins 115 are fixedly installed on the end surface of the left air chamber base 102, and three guide holes are set on the end surface of the left sliding plate 105. The guide holes correspond to the guide pins 115, and the ends of the guide pins 115 are located in the guide holes. When the left sliding plate 105 moves forward and backward, the guide pins 115 play a guiding role.

[0038] Four fine-tuning screws 116 can be provided on the left gland 104. The fine-tuning screws 116 are connected to the upper screw holes of the left gland 104. The ends of the fine-tuning screws 116 are pressed against the outer side of the left tension sleeve connecting shaft 109. The four fine-tuning screws are evenly distributed along the circumferential direction. The fine-tuning screws 116 are provided mainly to adjust the coaxiality of the left tension sleeve connecting shaft 109 and the first pull rod 110. When the fine-tuning screws 116 are used, the screws 113 are slightly loosened, and then the fine-tuning screws 116 are screwed to adjust the coaxiality of the left tension sleeve connecting shaft 109 and the first pull rod 110. The number of the fine-tuning screws 116 can be set to three.

[0039] Similarly, reference Figure 2 and 7 , multiple fine-tuning screws 722 can also be connected to the right gland 711 of the tailstock connection device 700, and the fine-tuning screws 722 are connected to the screw holes on the right gland 711, and the ends of the fine-tuning screws 722 are against the outer side of the right tension sleeve connecting shaft 718. The number of fine-tuning screws 722 can be three or four, and they are evenly distributed along the circumferential direction. The purpose of setting the fine-tuning screws 722 is mainly to adjust the coaxiality of the right tension sleeve connecting shaft 718 and the second pull rod 719. When using the fine-tuning screws 722, loosen the screws 720 slightly, and then screw the fine-tuning screws 722 to adjust the coaxiality of the right tension sleeve connecting shaft 718 and the second pull rod 719.

[0040] The pneumatic internal expansion tooling for machine tools performs internal support fixing on both ends of the pipe fitting to ensure coaxiality and ensure the processing quality of the pipe fitting. The operation is simple and fast, which is conducive to improving processing efficiency. It is not easy to be damaged after long-term use and does not need to be replaced. In some cases, the coaxiality between the right tension sleeve connecting shaft 718 and the second pull rod 719, the left tension sleeve connecting shaft 109 and the first pull rod 110, and the pipe fitting 300 can be improved by adjusting the fine-tuning screw 722 and the fine-tuning screw 116.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes.

Claims

1. A pneumatic internal expansion tool for a machine tool, characterized in that: Includes left chuck, tailstock connection device and air pipe; The left chuck comprises a left circular disc, a left air cavity base, a left pressure cover, a left sliding disc, a spring, a left tension sleeve connecting shaft, a first pull rod, a first nut seat, a bolt and a left tension sleeve. The left air cavity base is located between the left circular disc and the left pressure cover. A plurality of screws are first passed through the left pressure cover and then through the left air cavity base, and then connected with the threaded holes on the left circular disc. The air pipe passes through the left circular disc, and the end of the air pipe is fixedly connected to the left end of the left sliding disc. The left air cavity base is provided with a chamber, and the left sliding disc is located in the chamber. The base is provided with a central through hole, the left end of the left sliding disk is located in the central through hole of the air cavity base, the left end of the left sliding disk is slidably connected with the central through hole of the air cavity base, and a sealing ring is provided between the left end of the left sliding disk and the inner wall of the central through hole of the air cavity base; a sealing ring is connected between the periphery of the left sliding disk and the side wall of the chamber, and the left sliding disk can slide in the chamber; the end of the air pipe is provided with a side vent hole and a circumferential arc groove, the circumferential arc groove is connected with the side vent hole, and the side vent hole is connected with the air pipe The left end of the left sliding disk is provided with a plurality of air holes, and the plurality of air holes are connected with the side vents, and the plurality of air holes are connected with the chamber; the inner side surface of the left pressure cover is provided with a spring positioning groove, and the spring is located in the spring positioning groove, and the right end surface of the left sliding disk contacts the spring, and the number of springs is multiple; the left tensioning sleeve connecting shaft is fixedly connected to the outer side surface of the left pressure cover by screws, and the left tensioning sleeve connecting shaft is provided with a guide center through hole, and the first pull rod passes through the guide center through hole of the left tensioning sleeve connecting shaft and can slide; the left tensioning sleeve is sleeved on the right end of the first pull rod and the right end of the left tensioning sleeve connecting shaft; the first nut seat is fixedly connected to the central part of the right end surface of the left sliding disk by screws, and the left end of the first pull rod is provided with an external thread, and the external thread of the left end of the first pull rod is connected with the internal thread on the first nut seat; the outer edge of the end surface of the left circular disk is provided with an annular clamping boss, and a plurality of bolts pass through the left circular disk from the inside to the outside, and the plurality of bolts are evenly distributed along the circumferential direction of the left circular disk, and the thread head of each bolt is exposed outside; The tailstock connection device includes a support seat, a connecting shaft, a needle bearing, a tail positioning sleeve, a self-aligning ball bearing, an elastic retaining ring, a bearing retaining sleeve, a right air chamber base, a right pressure cover, a right sliding disk, a second nut seat, a right tension sleeve connecting shaft, a second pull rod and a right tension sleeve. The support seat is provided with an axial center through hole, the connecting shaft is located in the axial center through hole, the rear end of the connecting shaft is rotatably connected to the rear end of the support seat through a needle bearing, and the tail positioning sleeve is connected to the rear end of the support seat; the front end of the support seat is provided with a bearing chamber, the self-aligning ball bearing is located in the bearing chamber, and the front part of the connecting shaft is connected to the inner ring of the self-aligning ball bearing. The elastic retaining ring is located at the bottom of the bearing chamber at the front end of the support seat, the self-aligning ball bearing presses the elastic retaining ring, the bearing retaining sleeve is sleeved on the front part of the connecting shaft, and the bearing retaining sleeve is connected to the opening of the bearing chamber at the front end of the support seat; two sealing rings are connected between the connecting shaft and the support seat, and the front end of the connecting shaft is a disc part, which is fixedly connected to the right air cavity base by multiple screws; the support seat is provided with a compressed air inlet and outlet channel, and the connecting shaft is provided with a circumferential arc groove, a side air hole and an axial air hole, the side air hole is connected to the circumferential arc groove, the axial air hole is connected to the side air hole, and the compressed air inlet and outlet channel is connected to the side The air holes are connected; the two sealing rings between the connecting shaft and the support seat are located on both sides of the side air holes; the right air cavity base is provided with a chamber, and the central part of the right air cavity base is provided with a guide hole, and the guide hole is connected with the axial air hole of the connecting shaft; the right pressure cover is fixedly connected to the right air cavity base by multiple screws, the right sliding disk is located in the chamber of the right air cavity base, and a sealing ring is connected between the periphery of the right sliding disk and the side wall of the chamber of the right air cavity base, the inner side surface of the right pressure cover is provided with a spring positioning groove, and a spring is provided in the spring positioning groove of the right pressure cover, the left end surface of the right sliding disk is in contact with the spring on the right pressure cover, and multiple springs are provided; the The right end of the right sliding disk is provided with an axial air inlet hole and a side air inlet hole which are connected together, and there are multiple side air inlet holes, which are connected to the chamber of the right air cavity base; the right end of the right sliding disk is located in the guide hole of the right air cavity base (710) and can slide; the second nut seat is fixedly connected to the middle part of the left end surface of the right sliding disk by screws; the right tensioning sleeve connecting shaft is fixedly connected to the right pressure cover by multiple screws; the right tensioning sleeve connecting shaft is provided with a guide through hole, the second pull rod passes through the guide through hole of the right tensioning sleeve connecting shaft and can slide, and the right tensioning sleeve is sleeved on the left end portion of the second pull rod and the left end of the right tensioning sleeve connecting shaft.

2. The pneumatic internal expansion tooling for machine tools according to claim 1 is characterized in that: The end of the air pipe is inserted into the left end of the left sliding plate and fixed in an interference fit manner.

3. The pneumatic internal expansion tooling for machine tools according to claim 2 is characterized in that: The pneumatic internal expansion tooling for a machine tool further comprises a rotary joint, and the rotary joint is connected to the air pipe.

4. The pneumatic internal expansion tooling for machine tools according to claim 1 is characterized in that: Three guide pins are fixedly connected to the end surface of the left air cavity base, and three guide holes are arranged on the end surface of the left sliding plate. The guide holes correspond to and match the guide pins, and the ends of the guide pins are located in the guide holes.

5. The pneumatic internal expansion tooling for machine tools according to claim 1 is characterized in that: The left gland is connected with a fine-tuning screw, and the end of the fine-tuning screw abuts against the outer side of the left tension sleeve connecting shaft.

6. The pneumatic internal expansion tooling for machine tools according to claim 5, characterized in that: The number of the fine-tuning screws is three or four, and the three or four fine-tuning screws are evenly distributed along the circumferential direction.

7. The pneumatic internal expansion tooling for machine tools according to claim 1 or 5, characterized in that: The right gland is connected with a fine-tuning screw, and the end of the fine-tuning screw abuts against the outer side of the right tension sleeve connecting shaft.

8. The pneumatic internal expansion tooling for machine tools according to claim 7 is characterized in that: The number of the fine-tuning screws is three or four.

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