Machine tool

Abstract

Provide a machine tool with a simple structure and tool exchangeability. 【Solution means】 The machine tool 10 includes a frame 11, a ram 21 that is reciprocally arranged on the frame 11 and has a trigger hole 21a, a spindle 23 that can be equipped with a tool 1, is rotatably supported by the ram 21, and has a ring pin hole 23c, a drawbar 24 that has a collet 28, can reciprocate within the spindle 23, and is biased in the proximal direction of the spindle 23, an unclamping ring 31 that is arranged on the outer side in the radial direction of the spindle 23 and is connected to the drawbar 24 through the ring pin hole 23c, a trigger 35 that is fixed to the frame 11 and penetrates the trigger hole 21a, and a feed unit 38 that reciprocates the ram 21. The feed unit 38 advances the ram 21 in the tip direction to process the workpiece, retreats the ram 21 in the proximal direction, and makes the unclamping ring 31 contact the trigger 35, thereby advancing the drawbar 24 relative to the spindle 23 to open the collet 28.

Description

Technical Field

[0001] The present invention relates to a machine tool.

Background Art

[0002] For example, a drilling machine disclosed in Japanese Unexamined Patent Application Publication No. 2022-071706 is known. This drilling machine has a frame, a linear guide, a slider, a ram, a spindle, a spindle motor, a feed screw, and a feed motor. The frame has a linear guide support plate having a reference surface, a ram support plate having a ram guide hole, and a motor support portion. The linear guide is disposed on the reference surface. The slider reciprocates along the linear guide. The ram is disposed on the slider and penetrates through the ram guide hole. The spindle is pivotally supported within the ram. The spindle motor is connected to the spindle. The feed screw has a nut disposed on the slider and a screw shaft having one end pivotally supported by the motor support portion and the other end being a free end. The feed motor is connected to the screw shaft.

Summary of the Invention

Problems to be Solved by the Invention

[0003] An object of the present invention is to provide a machine tool with a simple structure and capable of tool exchange.

Means for Solving the Problems

[0004] A first aspect of the present invention is a frame, a hollow ram reciprocally disposed on the frame, the ram having a trigger hole penetrating in the radial direction and extending in the axial direction, a hollow spindle to which a tool can be attached and rotatably supported by the ram, the spindle having a ring pin hole penetrating in the radial direction and extending in the axial direction, a drawbar having a collet and reciprocating within the spindle, the drawbar being biased toward the proximal end of the spindle, An unclamping ring disposed radially outside the main shaft, the unclamping ring being connected to the drawbar through the ring pin hole, A trigger fixed to the frame and passing through the trigger hole, A feed unit for reciprocating the ram, Advancing the ram in the tip direction to machine the workpiece, Retracting the ram in the base end direction and bringing the unclamping ring into contact with the trigger, thereby advancing the drawbar with respect to the main shaft to open the collet, A feed unit, A machine tool having the above.

[0005] The machine tool is installed on a robot arm or a feed table. The machine tool rotates the main shaft, feeds out the ram (21), and performs milling, drilling, and tapping operations. The trigger may be a trigger block extending in a plane perpendicular to the main shaft. The trigger block is disposed between the main shaft and the ram. Preferably, the main shaft is supported by the ram at three points: the tip end portion, the central portion, and the base end portion of the main shaft. The support position of the central portion of the main shaft may be on the tip end side of the unclamping ring. The main shaft is supported by the ram by a main bearing. The guide block may be integral with the main shaft.

[0006] The machine tool may have an elastic body that biases the drawbar in the base end direction with respect to the main shaft. The elastic body is disposed between the draw shaft and the elastic body chamber. The elastic body may be disposed between the draw block and the elastic body chamber. The main shaft drive shaft is disposed coaxially with the main shaft. The main shaft drive shaft extends along the central axis of the main shaft. The unclamping ring has a contact surface that contacts the trigger. The contact surface is disposed at the base end portion of the unclamping ring.

Advantages of the Invention

[0007] According to the present invention, a machine tool with a simple structure and tool exchangeability can be provided.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0009] <Embodiment 1> As shown in FIGS. 1 to 3, the machine tool 10 of the present embodiment includes a frame 11, a linear guide 17, a connection block 19, a housing 13, a bearing 14, a drive shaft (main spindle drive shaft) 15, a ram 21, a main spindle bearing 22, a main spindle 23, a drawbar 24, a guide block 26, an anchor ring 31, a ring pin 33, a feed unit 38, a main spindle motor 41, a driving pulley (second driving pulley) 47, a driven pulley (second driven pulley) 45, and an endless belt (second endless belt) 48.

[0010] The feed unit 38 includes a feed screw 39, a bearing 32, a feed motor 43, a driving pulley (first driving pulley) 51, a driven pulley (first driven pulley) 49, and an endless belt (first endless belt) 52.

[0011] FIG. 1 is a cross-sectional view taken along line I-I in FIG. 2. Line I-I connects the central axis 3 of the main spindle 23, the central axis of the feed screw 39, and the center of the output shaft of the feed motor 43. The upper side of FIG. 1 is defined as the base end direction (+Z). The lower side of FIG. 1 is defined as the tip end direction (-Z). For convenience, the right direction in FIG. 1 is referred to as the lower side (+Y). For convenience, the left direction in FIG. 1 is referred to as the upper side (-Y). For convenience, the direction passing through the plane of FIG. 1 is referred to as the left-right direction (X).

[0012] The frame 11 is box-shaped. The frame 11 has a base plate 11a, a ram support plate 11b, a drive shaft support plate 11c, and side plates 11d (see Fig. 3). The ram support plate 11b has a ram hole 11f. The drive shaft support plate 11c has a housing hole 11g (see Fig. 3) and a screw support hole 11h. The ram hole 11f and the housing hole 11g extend along the central axis 3.

[0013] The linear guide 17 has a linear rail 17a and a linear block 17b. The linear rail 17a extends parallel to the central axis 3 and is arranged on the base plate 11a. The linear block 17b reciprocates on the linear rail 17a.

[0014] The connection block 19 connects the ram 21, the feed screw 39, and the linear block 17b. The connection block 19 is integrated with the ram 21 and reciprocates on the linear guide 17. The connection block 19 is in the shape of a rectangular plate. The lower end of the connection block 19 is fastened to the linear block 17b. The connection block 19 has a drive shaft hole 19a and a nut hole 19b. The drive shaft hole 19a is arranged at the lower part of the connection block 19. The nut hole 19b is arranged at the upper part of the connection block 19. The drive shaft hole 19a extends along the central axis 3 and penetrates the connection block 19.

[0015] As shown in Fig. 1, the housing 13 is in a hollow cylindrical shape and is arranged in the housing hole 11g. Preferably, the housing 13 can be inserted into the housing hole 11g from the proximal end direction (+Z direction). The housing 13 supports the drive shaft 15 via a bearing 14. The housing 13 may be integrated with the drive shaft support plate 11c. The housing 13, the bearing 14, and the drive shaft 15 can be removed from the frame 11 as a whole.

[0016] As shown in Fig. 3, the drive shaft 15 has a spline shaft 15a, a support shaft 15b, a coolant passage (first coolant passage) 15c, and a supply port (coolant supply port) 15d. The drive shaft 15 extends along the central axis 3 and penetrates the drive shaft hole 19a. The base end portion of the drive shaft 15 is supported by the housing 13. The base end portion of the drive shaft 15 protrudes to the base end side from the housing 13 and the drive shaft support plate 11c. The spline shaft 15a is disposed at the central portion of the drive shaft 15 in the axial direction. The support shaft 15b is disposed at the tip of the drive shaft 15. The support shaft 15b is a straight cylinder. The coolant passage 15c extends along the central axis 3 and penetrates the drive shaft 15. The supply port 15d is disposed at the base end of the drive shaft 15 and is connected to the coolant passage 15c. The supply port 15d is, for example, a female pipe thread.

[0017] The ram 21 is a hollow cylindrical shape and extends along the central axis 3. The base end portion of the ram 21 is fastened to the connection block 19. The tip end portion of the ram 21 penetrates the ram hole 11f. The ram 21 slides axially with respect to the ram hole 11f. The ram 21 reciprocates integrally with the connection block 19. As shown in Fig. 3, the ram 21 has a trigger hole 21a. The trigger hole 21a is disposed on the left - right plane (ZX plane). The left - right plane (ZX plane) is a plane that passes through the central axis 3 and extends in the left - right direction. The trigger hole 21a penetrates the ram 21 in the radial direction. The trigger hole 21a is a long hole extending in the axial direction.

[0018] The main shaft 23 is a hollow cylindrical shape and extends along the central axis 3. The main shaft 23 is supported by the ram 21 via the main bearing 22. As shown in Fig. 3, the main shaft 23 has, in order from the base end portion, a spline hole 23a, a drive shaft chamber 23b, a spring chamber (elastic body chamber) 23d, a through - hole 23e, a collet chamber 23f, and a main shaft hole 23g. The spline hole 23a meshes with the spline shaft 15a. The drive shaft chamber 23b is connected to the spline hole 23a and the spring chamber 23d. The main shaft hole 23g is connected to the collet chamber 23f. The through - hole 23e connects the collet chamber 23f and the spring chamber 23d. The tool 1 is attached to the main shaft hole 23g. The tool 1 has a stud bolt 1b.

[0019] The guide block 26 is a hollow straight cylinder. The guide block 26 has an outer surface 26a and a guide hole 26b. The outer surface 26a abuts against the inner surface of the drive shaft chamber 23b and slides in the axial direction. The guide hole 26b abuts against the outer surface of the support shaft 15b. The guide hole 26b slides in the axial direction with the support shaft 15b. The support shaft 15b is supported by the main shaft 23 via the guide block 26. The guide hole 26b is a part of the second coolant flow path.

[0020] The drawbar 24 is disposed at the tip of the main shaft 23. The drawbar 24 reciprocates inside the main shaft 23. The drawbar 24 has a draw block 25, a draw shaft 27, and a collet 28. As shown in FIG. 3, the draw block 25 is hollow cylindrical. The draw block 25 has a body 25a, a shaft support hole 25d, a coolant flow path (second coolant flow path) 25c, and a pin fixing hole 25e.

[0021] The body 25a is connected to the guide block 26. The shaft support hole 25d and the coolant flow path 25c extend along the central axis 3. The shaft support hole 25d is disposed at the tip of the body 25a and opens at the tip of the body 25a. The coolant flow path 25c connects the guide hole 26b and the shaft support hole 25d. The pin fixing hole 25e extends in the radial direction and penetrates the body 25a. The pin fixing hole 25e is a cylindrical hole.

[0022] The draw shaft 27 is hollow cylindrical. The draw shaft 27 penetrates through the through hole 23e and is fastened to the shaft support hole 25d. The draw shaft 27 has a coolant flow path (second coolant flow path) 27b. The collet 28 grips the stud bolt 1b of the tool 1. The collet 28 is disposed at the tip of the draw shaft 27. The collet 28 is disposed in the collet chamber 23f.

[0023] The disc spring 29 is disposed in the spring chamber 23d. The disc spring 29 biases the drawbar 24 in the proximal direction. The unclamping ring 31 is in the shape of a hollow cylinder and is arranged at the central part of the main shaft 23. The unclamping ring 31 can slide on the outer peripheral surface of the main shaft 23. As shown in FIG. 1, the unclamping ring 31 has a pin hole 31a and a contact surface 31b. The pin hole 31a extends in the radial direction and penetrates the unclamping ring 31. The contact surface 31b is arranged at the rear end of the unclamping ring 31.

[0024] The ring pin 33 is arranged to penetrate through the pin hole 31a, the ring pin hole 23c, and the pin fixing hole 25e. The ring pin 33 connects the drawbar 24 and the unclamping ring 31. The ring pin 33 has a coolant flow path (second coolant flow path) 33a (see FIG. 1). The ring pin 33 reciprocates inside the ring pin hole 23c integrally with the drawbar 24 and the unclamping ring 31.

[0025] As shown in FIG. 3, a pair of clamping pins (triggers) 35 extend from the left and right (X direction) toward the central axis 3. The clamping pin 35 has a head 35b and a pin 35a. The head 35b is fixed to the side plate 11d. The pin 35a penetrates through the trigger hole 21a and protrudes into the inside of the ram 21. When the ram 21 retracts, the pin 35a can contact the contact surface 31b.

[0026] As shown in FIG. 1, the feed motor 43 is arranged on the drive shaft support plate 11c. The driving pulley 51 is connected to the feed motor 43. The feed screw 39 has a screw shaft 39a and a nut 39b. The screw shaft 39a is supported by the ram support plate 11b via a bearing 32. Also, the screw shaft 39a is supported by the drive shaft support plate 11c via a bearing 40. The nut 39b is inserted into the nut hole 19b and fastened to the connection block 19. The base end portion of the screw shaft 39a protrudes to the rear of the drive shaft support plate 11c. The driven pulley 49 is fastened to the base end portion of the screw shaft 39a. An endless belt 52 is stretched between the driving pulley 51 and the driven pulley 49.

[0027] As shown in Fig. 2, the main shaft motor 41 is installed on the drive shaft support plate 11c. The driving pulley 47 is connected to the main shaft motor 41. The driven pulley 45 is arranged at the base end of the drive shaft 15. The endless belt 48 is stretched between the driving pulley 47 and the driven pulley 45.

[0028] As shown in Fig. 3, the coolant device 55 is connected to the supply port 15d. The coolant device 55 supplies coolant to the machine tool 10. The coolant is, for example, liquid coolant, mist coolant, or gas coolant.

[0029] The tool 1 is mounted in the spindle hole 23g by a tool changer (not shown), a robot (not shown), or an operator. When the ram 21 is fed in the tip direction by the feed unit 38, the drawbar 24 is pulled in the base end direction by the disc spring 29. Then, the collet 28 grips the stud bolt 1b and brings the tool 1 into close contact with the spindle hole 23g. The feed unit 38 further feeds the ram 21 in the tip direction, and the tool 1 mounted on the spindle 23 processes the workpiece. The tool 1 performs, for example, milling, drilling, or tapping.

[0030] When the ram 21 is fed in the base end direction by the feed unit 38, the contact surface 31b contacts the unclamping pin 35. When the feed unit 38 continues to feed the ram 21 in the base end direction, the clamping ring 31 is pressed by the unclamping pin 35. Then, against the elastic force of the disc spring 29, the drawbar 24 advances with respect to the spindle 23. As a result, the collet 28 releases the stud bolt 1b and pushes out the tool 1 from the spindle hole 23g.

[0031] According to the machine tool 10 of this embodiment, by simply feeding the ram 21 in the base end direction by the feed unit 38, the drawbar 24 can advance relative to the spindle 23 to unclamp the tool 1. Then, by simply feeding the ram 21 in the tip direction by the feed unit 38, the drawbar 24 can clamp the tool 1. The machine tool 10 has a simple structure and can exchange the tool 1. The machine tool 10 can perform drilling, tapping, milling, etc. by further feeding out the ram 21. The unclamping pin 35 is directly arranged on the frame 11. Therefore, the disc spring 29 can increase the force for pulling the drawbar 24.

[0032] Both ends of the drive shaft 15 are supported by the bearing 14 and the spindle 23. Therefore, the circumferential runout of the drive shaft 15 is suppressed. Thereby, the rotational speed of the spindle 23 can be increased.

[0033] As shown in FIG. 3, the coolant supplied from the supply port 15d is supplied to the tool 1 through the coolant flow paths 15c, 25c, 33a, 27b and the collet 28. For this reason, the machine tool 10 can supply the coolant to the machining point from the tip of the cutting edge of the tool 1 or between the cutting edge and the tool holder through the tool holder. The support shaft 15b is supported by the guide block 26. The guide block 26 is integral with the drawbar 24. And the coolant flow path 15c is directly connected to the coolant flow paths 25c, 27b of the drawbar 24. Therefore, the coolant flow path 15c has fewer connection parts and a small cross-sectional change. Thereby, the pressure loss of the coolant is suppressed. Also, when the coolant is mist coolant, the separation of the mist is suppressed.

[0034] <Embodiment 2> As shown in FIGS. 4 to 6, the machine tool 100 of this embodiment has a ram 121, a guide block 126, a drawbar 124, and a trigger block (trigger) 135. Other configurations of the machine tool 100 are substantially the same as those of the machine tool 10 of Embodiment 1. FIG. 4 is a sectional view taken along line IV-IV of FIG. 5.

[0035] The ram 121 has trigger holes 121a. As shown in FIG. 5, the ram 121 has a pair of trigger holes 121a in the left-right direction (X direction) with respect to the central axis 3. The trigger holes 121a penetrate the ram 121 in the up-down direction (Y direction). As shown in FIG. 6, the trigger holes 121a extend in the front-rear direction (Z direction). Other configurations of the ram 121 are substantially the same as those of the ram 21 in Embodiment 1.

[0036] As shown in FIG. 4, the guide block 126 is a hollow cylinder and is integral with the main shaft 23. The guide block 126 has a guide hole 126b. The guide hole 126b extends along the central axis 3. The guide hole 126b supports the support shaft 15b. The support shaft 15b slides axially with respect to the guide hole 126b.

[0037] The drawbar 124 has a draw block 125, a draw shaft 27, and a collet 28. The drawbar 124 reciprocates inside the main shaft 23 independently of the guide block 126. The draw block 125 has a body 125a, a coolant flow path 125c, a shaft support hole 25d, and a pin fixing hole 25e. The body 125a is separate from the guide block 126. The coolant flow path 125c is substantially the same as the coolant flow path 25c in Embodiment 1.

[0038] As shown in FIG. 5, the trigger block 135 is U-shaped in a front view. The trigger block 135 is disposed on the base plate 11a. The trigger block 135 has a pair of triggers 135a and a connecting block 135b. As shown in FIG. 5, the trigger 135a is in the shape of a rectangular plate. As shown in FIG. 5, the trigger 135a extends in the up-down direction (Y direction) and penetrates the trigger holes 121a respectively. The connecting block 135b connects the pair of triggers 135a and is fastened to the base plate 11a.

[0039] According to the machine tool 100 of the present embodiment, the second moment of area in the longitudinal direction (Z direction) of the trigger 135a increases. Therefore, the elastic force of the disc spring 29 can be made larger than that of the machine tool 10 of the first embodiment.

[0040] The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present invention. All technical matters included in the technical idea described in the claims are the subject of the present invention. The above embodiments show preferred examples, but those skilled in the art can realize various alternative examples, modified examples, deformed examples, or improved examples from the content disclosed in this specification, and these are included in the technical scope described in the appended claims.

Explanation of Reference Numerals

[0041] 10, 100 Machine tool 11 Frame 21, 121 Ram 21a, 121a Trigger hole 23 Spindle 23c Ring pin hole 24 Drawbar 35, 135 Trigger 38 Feed unit

Claims

1. A frame, A hollow ram that is reciprocally disposed on the frame, the ram having a trigger hole that penetrates the ram in the radial direction and extends in the axial direction, A hollow spindle to which a tool can be attached and that is rotatably supported on the ram, the spindle having a ring pin hole that penetrates the spindle in the radial direction and extends in the axial direction, A drawbar having a collet, the drawbar being reciprocable within the spindle and being biased in the proximal end direction of the spindle, An unclamping ring disposed outside the spindle in the radial direction, the unclamping ring being connected to the drawbar through the ring pin hole, A trigger fixed to the frame and penetrating the trigger hole, A feed unit for reciprocating the ram, Advancing the ram in the tip direction to machine a workpiece, Retracting the ram in the proximal end direction and bringing the unclamping ring into contact with the trigger to advance the drawbar relative to the spindle and open the collet, The feed unit, A machine tool having the above.

2. The feed unit closes the collet by advancing the ram in the tip direction and retracting the drawbar relative to the spindle. The machine tool according to Claim 1.

3. The trigger is a clamping pin that extends perpendicular to the spindle. The machine tool according to Claim 1 or 2.

4. Further comprising a ring pin that penetrates the ring pin hole and connects the unclamping ring and the drawbar. The machine tool according to Claim 1 or 2.

5. The drawbar, A draw shaft connected to the collet, A draw block connected to the proximal end direction of the draw shaft, Having the above, The ring pin penetrates the draw block. The machine tool according to Claim 4.

6. The spindle has a spline hole disposed at the base end portion, Further comprising a spindle drive shaft having a spline shaft that is inserted into the spline hole, meshes with the spline hole, and transmits rotation, The frame, A ram support plate that slidably supports the tip portion of the ram in the front - rear direction, A drive shaft support plate that rotatably supports the spindle drive shaft, Having the above, The machine tool according to Claim 1 or 2.

7. A linear guide that extends in the direction of the spindle and is disposed on the frame, A connection block that is guided by the linear guide, connected to the ram, and is reciprocable, Further having the above, The machine tool according to claim 1 or 2.

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