JPH031128Y2 - - Google Patents

Description

[Detailed description of the invention] (1) Industrial technical field The present invention relates to a tool locking device for a machine tool, particularly a small machining center.

(2) Conventional technology A wide variety of tool locking devices have been used in the past for inserting and locking a tool holder holding a tool onto a main spindle that is rotatably fitted and supported in the main spindle head of a machine tool, particularly a small machining center. is known and used.

A typical known tool locking system for a machine tool, particularly using a collect, is shown in FIGS. 2 and 3. In FIG. 2A, the tool holder 3 is inserted into the tool holder insertion hole 2 from the tip of the main spindle 1, while the drawbar 7 inserted into the collet 6 and fixed with the screw 7a is inserted into the rear end of the main spindle 1. It is inserted into the through hole 4 from above.
The pull stud 5, which is the rear end of the tool holder 3, is locked and unlocked on the inner surface of the tip 6a of the collet 6.

(3) Problem to be solved When locking the prill stud 5, which is the rear end of the tool holder 3, with the tip 6a of the collet 6,
The shapes of the locking portions of the pull stud 5 and the tip 6a of the collet 6 are shown as an inclined surface (45 degrees in this embodiment) in FIG. 2A and 0 degrees in FIG. 2B. In addition, the collet 6 in Figure 2A is constructed so that it is always expanded by its own spring force, and the collet 6 in Figure 2B is constructed so that it is always in the contracted position as shown in the figure by its own spring force. has been done.
In FIGS. 2A and 2B, when the collet 6 and drawbar 7 are assembled and disassembled from the rear of the main spindle 1, the collet 6 and the drawbar 7 can be attached and detached at the same time. However, due to the difference in shape due to the functional difference in the collet 6, the shape of the inner diameter portion of the main spindle 1 is different. That is, in FIG. 2A, since the shape of the locking portion of the collet tip 6a has an inclined surface (45 degrees in this example), the reaction force generated at the time of locking is generated in the direction of expanding the collet tip 6a. A component force is generated, and therefore, it is necessary to restrict the opening by using the through hole 4 of the main spindle 1 as an inner wall. In Fig. 2B, the shape of the locking portion of the collet tip 6a is 0 degrees, and although the component force described above does not occur, the collet tip is It is necessary to provide a gap between the portion 6a and the inner wall of the main spindle 1. Therefore, if the tool holders 3 in FIG. 2A and FIG. 2B are to be replaced due to the difference in the shape of the lock portion of the pull stud 5, the respective main spindles 1 must be replaced, resulting in no compatibility. It is also possible to make the structures of the inner diameter parts of the collet 6, drawbar 7, and main spindle 1 in Fig. 2B the same as in Fig. 2A, and only the shape of the lock part of the collet tip 6a to be 0 degrees to maintain compatibility. Conceivable.
However, in such a structure, bending stress due to the 0 degree shape is generated in the slotted part 61 (thin wall part) of the collet 6 due to the tensile force during locking, making it difficult to reduce the wall thickness. Can not. Further, even if the thickness of the slotted portion 61 is made thinner, the bending stress of the root portion 62 increases, resulting in damage. Therefore, when the shape of the lock portion is 0 degrees, the structure shown in FIG. 2A is not desirable.

3A and 3B show other conventional examples in which the shape of the inner diameter part in the main shaft spindle 1 is made the same, and the tips 6a of the pull stud 5 and the collet 6 are
Fig. 3A shows an example in which the shape of the locking part is an inclined surface (45 degrees in the embodiment), and Fig. 3B shows an example in which the shape is 0 degrees.
In other words, the shape of the inner diameter inside the main spindle 1 was made the same to make the main spindle 1 compatible, but the collet 6 and drawbar 7 were assembled from the rear,
When disassembling, especially when disassembling and pulling out, it is necessary to first pull out the drawbar 7 while pushing the collet 6 forward, and then pull out the collet 6, and currently it is not possible to pull it out at the same time.

In this way, in the cases shown in Figure 2 A and B, it is possible to pull out the collet 6 and drawbar 7 at the same time, but
The main spindle 1 itself must be replaced,
In addition, in the case of Fig. 3 A and B, the main spindle 1
Although we have created compatibility so that the collet 6 and drawbar 7 cannot be removed at the same time, there are advantages and disadvantages.

Therefore, the conventional tool lock device has the problem that assembly and disassembly operations require manual labor and are very troublesome.

(4) Purpose The purpose of this invention was proposed in order to solve the problem in view of the above circumstances, and to provide compatibility without replacing the main spindle, and to connect the collet and drawbar to the main spindle. To provide a tool locking device for a machine tool which facilitates assembly and disassembly by simultaneously pulling out from the rear of the tool.

(5) Means and operation for solving the problems The present invention is an improvement of a tool locking device for a machine tool that locks and unlocks a tool holder within a main spindle.

That is, a first inner wall portion having a larger diameter and having a sloped portion relative to the through hole and a second inner wall portion having a larger diameter having a slope sloped from the first inner wall portion are provided at the inner diameter portion of the main shaft spindle. Therefore, when using a collet that is inserted into the inner wall of the main spindle and has an angle (inclined surface) to apply component force, the outer periphery of the tip of the collet will be the first inner wall when the lock is locked, and the outer periphery of the collet tip will be the first inner wall when the lock is unlocked. When the outer periphery of the collet tip expands within the second inner wall and is removed from the rear of the main spindle,
The tip of the drawbar is made into an inclined portion so that the tip of the collet is compressed and can be slid from the through hole. In addition, when using a collet with an angle of 0 degrees and no component force applied, the outer periphery of the collet tip has a gap with the inner wall of the through hole when locked, and the outer periphery of the collet tip has a gap with the first inner wall when unlocked. It is configured to be expanded within the department. in this way,
A first inner wall part and a second inner wall part are provided on the inner wall part of the main spindle, and the collet structure is divided into cases where the angle is 0 degrees and more, and the collet is inserted into the through hole of the main spindle from the rear of the main spindle. At the very least, the collet and drawbar are slid in the axial direction of the main spindle in order to lock and unlock the pull stud of the tool holder at the tip of the collet. As a result, when assembling and disassembling the main spindle with the same inner wall structure, the collet and drawbar can be inserted and removed at the same time from the rear of the main spindle.

(6) Example Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

1A and 1B are front sectional views of an embodiment of the tool locking device of the present invention. In FIGS. 1A and 1B, the inner wall shapes of the main spindles are made the same to provide compatibility.

In FIG. 1A, a tool holder 3 is inserted into a tool holder insertion hole 2 formed at the tip of the main spindle 1. The collet 6 is inserted into the through hole 4 formed in the main spindle 1 from the rear of the main spindle 1, and the drawbar 7 fixed with a screw 7d is inserted. A plurality of disc springs 8 are inserted between the rear shaft 7a of the drawbar 7 and the main shaft spindle 1, and are normally pulled rearward.

In the through hole 4 of the main shaft spindle 1, a through hole 4a having a slightly larger diameter than the through hole 4 is formed after the rear part of the inserted collet 6, and the through hole 4 is connected to the through hole 4a.
By pressing the drawbar 7 forward from the rear of the main spindle 1 in the direction of the arrow 1 at the stepped portion A of the main spindle 1, the collet 6 slides forward together with the drawbar 7, and the rear end 6c of the collet 6 slides forward.
comes into contact with the stepped portion A and restricts further sliding. That is, the distance l is the stroke of the collect 6.

A pull stud 5 is fixed to the rear end of the tool holder 3, and a sloped portion 5 is locked with a collet 6.
a and the inclined portion 6b of the lower jaw portion of the tip 6a of the collet 6, each forming an angle of 45 degrees. In order to lock and unlock the pull stud 5 of the tool holder 3 and the tip 6a of the collet 6, a first inner wall portion 4b having an inclined portion slightly larger than the diameter of the through hole 4 is provided at the forward end of the inner wall portion of the main spindle 1. A second inner wall portion 4c having an inclined portion having a larger diameter than the first inner wall portion 4b is provided. The diameter of the first inner wall portion 4b is such that the collet 6 is slid forward, and the tip portion 6a of the collet 6 is opened by the spring force of the collet itself.
The minimum diameter is sufficient as long as the pull stud 5 can be pulled out from the tip of the main spindle 1. The angle of inclination of the inclined part B, which is the boundary between the first inner wall part 4b and the second inner wall part 4c, is approximately the same as the angle of inclination of the shoulder part C of the tip part 6a of the collet 6. The collet 6 is designed to easily expand when C slides forward and enters the unlocked state.

The diameter of the first inner wall portion 4b is approximately midway between the diameters of the through hole 4 and the second inner wall portion 4c, and when the tip of the 0 degree collet, which will be described later, is in an unlocked state, the pull stud 5 of the tool holder 3 can be opened from the front. The minimum diameter is sufficient to make it free for coming out. Through hole 4
The angle of inclination of the inclined portion D, which is the boundary between the first inner wall portion 4b and the first inner wall portion 4b, is such that the shoulder portion E of the 0-degree collet, which will be described later, can easily expand when unlocked.

In addition, the drawbar 7, which is one of the main parts of the present invention,
The distal end 7b is inclined toward the most distal end,
The angle of inclination and the length of the inclination are determined so that when the drawbar 7 and the collet 6 are removed from the rear of the main spindle 1, the tip 6a of the collet 6 can contract and slide within the through hole 4.

Therefore, the present invention is applicable to any tool holder e.g.
The through hole in the main spindle 1 is made into the same shape so that it can be used at 45 degrees and 0 degrees, and the drawbar 7 and the collet 6 can be pulled out from the rear of the main spindle 1 at the same time.

Next, the operation of the example of the present invention shown in FIG. 1A will be explained.

(a) A screw 7d is inserted into the through hole 4 of the main spindle 1.
When assembling the collet 6 and drawbar 7, which are fixed together, they are inserted into the main spindle 1 from the rear with the nut 9 removed.

(b) A hydraulic cylinder (not shown) pushes the drawbar 7 forward in the direction of the arrow 1 in the figure, and the collector 6
The rear end portion 6c is brought into contact with the stepped portion A between the through hole 4 and the through hole 4a.

At this time, the tip end 6a of the collet 6 is expanded by the spring force of the collet 6 itself and maintained in the expanded state within the second inner wall portion 4c.

(c) Insert the tool holder 3 into the tool holder insertion hole 2 from the front of the main spindle 1.

(d) When locking, the drawbar 7 is
By pulling the collet 6 backward, the collet 6 is also pulled rearward at the same time, and the tip 6 of the collet 6
a slides along the first inner wall portion 4b while tightening, and the inclined portion 6b of the lower jaw portion of the tip portion 6a of the collet hits the inclined portion 5a of the pull stud 5 and is locked.

(e) When unlocking, push the drawbar 7 forward in the direction of arrow 1 using a hydraulic cylinder (not shown) to bring it into the state shown in (b) above, with the end surface of the tip 7b of the drawbar 7 touching the rear end surface of the pull stud 5. The contact tool holder 3 is unlocked so that it can be passed forward.

(f) When replacing the drawbar 7 and collet 6 from the main spindle 1, remove the tool holder 3 from the front of the main spindle 1 in the unlocked state and replace it, and then remove the hydraulic cylinder (not shown) and then replace the drawbar 7 and the collect. 6 from the rear of the main spindle 1, the tip of the collet contracts and comes into close contact with the inclined part of the tip 7b of the drawbar 7, and the outer periphery of the tip of the collet fits into the wall of the through hole 4. By sliding the drawbar 7 and the collet 6, the drawbar 7 and the collet 6 come out at the same time.

FIG. 1B shows a case where the shape of the locking part is 0 degrees, and the structure and shape are almost the same as FIG. 1B.

The difference is that the shape of the tip of the drawbar 7 and the shape of the tip of the collet 6 are different.

Further, the collet 6 does not have the spring force to expand by itself. Therefore, when the collet is expanded to be in the unlocked state, the tip 7b of the drawbar 7 has a slanted portion 7c that presses the slanted surface 6d of the collet 6 when the collet 6 is pushed forward of the main spindle 1. As a result, the tip 6a of the collet 6 expands within the first inner wall 4b. In this state, the tool holder 3 can be easily pulled out from the front of the main spindle 1. Further, the fixed position at the time of unlocking is restricted by the shoulder C of the collet 6 abutting against the stepped portion A.

Next, the operation will be explained.

(a) Connect the collet 6 and drawbar 7 to the main spindle 1
When assembling into the through hole 4 of the main spindle 1
The collet 6 and drawbar 7 are inserted into the through hole 4 of the main shaft spindle 1 from behind.

(b) A hydraulic cylinder (not shown) pushes the drawbar 7 forward to move the rear end 6c of the collet 6 until it abuts against the step A between the through hole 4 and the through hole 4a.

At this time, the tip 7b of the drawbar 7 is pressed against the inclined surface 6d of the collet 6, and the outer periphery of the tip of the collet expands within the first inner wall 4b. The most extreme part of the tip 6a is in a state in which the pull stud 5 can be inserted.

(c) Insert the tool holder 3 into the tool holder insertion hole 2 from the front of the main spindle 1.

(d) Disc spring 8 provided on the rear shaft 7a of the drawbar 7
When the drawbar 7 is pulled rearward by the urging force of The lower jaw portion 6e of the tip portion 6a of the collet contacts the shoulder portion 5a of the pull stud 5 and is locked.

(E) When unlocking, push the drawbar 7 forward as shown by the arrow with a hydraulic cylinder (not shown), so that the state shown in (B) is reached, and the end face of the tip 7b of the drawbar 7 comes into contact with the rear end face of the pull stud 5, and the tool The holder 3 is unlocked so that it can be pulled out forward.

(F) Move the collet 6 and drawbar 7 to the main spindle 1
When removing from the through hole 4 of the tool holder 3
After removing the hydraulic cylinder (not shown) from the front of the main spindle 1, and pulling the drawbar 7 and the collet 6 from the rear of the main spindle 1, the outer periphery of the collet tip 6a is inserted into the through hole 4. The drawbar 7 and the collect 6 come out at the same time by sliding on the wall.

(7) Effects The tool locking device of the present invention makes the inner diameter shape of the main spindle the same and improves the shapes of the collet and rover. Since the drawbar and collet can be inserted and removed at the same time from the rear of the spindle, assembly and disassembly work is facilitated.

Furthermore, the working time for assembly and disassembly is greatly reduced, further improving work efficiency. Further, since it can be used with various types of tool holders without replacing the main spindle, it can be made more versatile.

[Brief explanation of the drawing]

1A and 1B are cross-sectional front views of the inside of the main spindle showing the tool locking device of the present invention. Second
Figures A and B are cross-sectional front views of the inside of the main spindle, showing a conventional tool locking device. Figure 3 A,
B is a sectional front view of the inside of the main spindle showing another conventional tool locking device. 1...Main shaft spindle, 3...Tool holder,
4, 4a...through hole, 4b...first inner wall part, 4
c...Second inner wall portion, 5...Pull stud, 5a
... Inclined portion, 6... Collet, 6a... Collet tip, 6b... Collet slope, 6c... Collet rear end, 6d... Collet slope, 6e...
Lower jaw part of collet tip, 7... Drawbar, 7
a... Drawbar shaft, 7b... Drawbar tip,
7c... Slanted part, 8... Belleville spring, A... Stepped part,
B, D... Slope part, C, E... Shoulder part of the collect.

Claims (1)

[Scope of utility model registration request] A tool locking device for a machine tool that locks and unlocks a tool holder within a main spindle, the tool locking device having a first inner wall portion having a diameter larger than a through hole at an inner diameter portion of the main spindle, and a second inner wall portion having a diameter larger than the first inner wall portion. When using a collet that has a second inner wall and is angled to apply a component force, the outer periphery of the collet tip contracts with the first inner wall when locked, and the outer periphery of the collet tip contracts with the second inner wall when unlocked. The tip of the drawbar is sloped so that it expands on the inner wall of the drawbar and the collet can slide through the through hole, and when using a collet that does not have an inclination angle and does not apply component force, it The outer periphery of the collet tip is positioned with a gap within the wall of the through hole, and the outer periphery of the collet tip is expanded at the first inner wall by a drawbar when unlocked;
A tool lock device for a machine tool, characterized in that a collet and a drawbar can be inserted and removed at the same time from behind the main spindle during assembly and disassembly.