JPS5943044Y2 - Check - Google Patents

Description

[Detailed description of the invention] The present invention relates to a chuck with a safety device that grips tools, collets, etc. via a clutch mechanism that becomes disconnected when a torque exceeding the transmission limit torque value is applied. It is an object of the present invention to prevent fluctuations in the limit torque value and to easily finely adjust the transmission limit torque value.

In a general chuck equipped with a clutch mechanism that serves as a safety device, a chuck opening into which a tool or a collet to be gripped is inserted is formed on the tip side of the main body, and a chuck opening into which an object to be gripped in the chuck opening is inserted is formed on the tip side. A plurality of clutch bodies are provided in the circumferential direction so as to be freely movable in the radial direction and to rotate the main body and the grasped object together. A torque rubber is inserted in a compressed manner to bias the clutch body inward in the radial direction. , the clutch body moves backward while compressing the torque rubber, disengages from the engaged state with the object to be grasped, and cuts off the power transmission path between the main body and the object to be grasped. This is to prevent breakage or damage.

However, in the above-mentioned chuck, the torque rubber hardens over time and the set transmission limit torque value tends to fluctuate and become high.As a result, even if an excessive load is applied to the object to be gripped, the power transmission is difficult. The reality is that there is a high risk that the path will not be blocked and the object to be gripped will be broken or damaged.

Also, as mentioned above, since torque rubber is used,
There were also difficulties in oil resistance, water resistance, and heat resistance.

Furthermore, with the chuck described above, there is a problem in that the transmission limit torque value cannot be finely adjusted.

The present invention was devised in view of the above-mentioned circumstances, and its feature is that a chuck opening is formed in the axial direction on the tip side of the main body into which an object to be gripped, such as a tool or collet, can be inserted and removed. At the same time, the tip side removably engages with the object to be grasped in the chuck mouth, causing the main body and the object to be rotated together, and when a torque of more than a set value is applied, there is no contact with the object to be grasped. The clutch body to be disengaged from the engaged state is movable in the radial direction and is mounted on a plurality of chucks provided in the circumferential direction.
An inner cylindrical body that is expandable and contractible in the radial direction and has a tapered outer circumferential surface is provided on the outer periphery of the tip side of the main body, and is fitted onto the clutch body, and between the inner cylindrical body and the clutch body, the clutch body A spring is inserted in a resilient manner to urge the radially inward direction, and an outer cylinder body with a tapered inner circumferential surface is fitted onto the inner cylinder body so as to be slidable in the axial direction. An adjusting nut for sliding the outer cylindrical body in the axial direction with respect to the inner cylindrical body is screwed onto the outer periphery of the distal end side of the main body so as to be freely movable in the axial direction.

Hereinafter, one embodiment of the present invention will be described based on the drawings of FIGS. 1 and 2. 1 is tapered connected to the main spindle head (not shown) of a machine tool through a fitting fixing cylinder 2 at the base. This is a chuck main body, and a fixing flange 3 is integrally formed in the middle part of the main body 1 in the longitudinal direction, and a grasped object 4 such as a tool or a collet is inserted into and removed from the tip side of the main body 1. A chuck opening 5 is formed in the axial direction from the tip.

Further, on the distal end side of the main body 1, a clutch body equipment portion T is formed which is sandwiched between the fixing flange 3 and the distal large diameter portion 6 and has a smaller diameter than these.

The equipment part γ has a hexagonal outer circumference, and this equipment part has
A plurality of clutch bodies 8 (six in the illustrated example) equally distributed in the circumferential direction are inserted into the chassis 5 so as to be immovable in the circumferential direction but slidable in the radial direction.

The clutch body 8 includes a rectangular parallelepiped-shaped coupling piece 9 that is inserted into the equipment part T, a spring receiver piece 10 that is wider than the coupling piece 9 and is fixed to the outer surface of the coupling piece 9, and a coupling piece 9. The pieces 9 and the receivers each include spring pins 11, etc., which protrude outward in the radial direction and are arranged as a pair in the axial direction.

The coupling piece 9 removably engages with the engagement recess 13 of the engagement body 12 attached to the object 4 to be grasped, thereby causing the main body 1 and the object 4 to rotate together.

The engagement recess 13 is formed over the entire length of the engagement body 12 in the axial direction, and has a shape that gradually expands from the axial direction (towards the radial direction when viewed from the outside). The distal end side is also shaped in a corresponding manner, so that when a torque equal to or greater than the transmission limit torque value is applied to the coupling piece 9, the coupling piece 9 separates from the engagement recess 13 radially outward.

Further, both ends of the coupling piece 9 in the axial direction are chamfered.

Reference numeral 14 denotes an inner cylindrical body which is fitted onto the equipment portion T, and is fitted between the fixing flange 3 and the large diameter portion 6.

The inner cylindrical body 14 has a tapered shape toward the tip of the outer peripheral surface of the furnace body 1, and is equally divided into a plurality of (two in the illustrated example) divided bodies 15 in the circumferential direction. It is said that it can be expanded and contracted in the radial direction.

Note that a bolt 16 is screwed in the axial direction from the tip surface of the large diameter portion 6, and by inserting the bolt 16 into the gap 17 between the divided bodies 15, the relative relationship between the main body 1 and the inner cylindrical body 14 is fixed. Rotation is prevented.

A spring bearing part 18 corresponding to the pin 11 of the clutch body 8 is recessed radially outward on the inner peripheral part of the inner cylinder body 14.
A coiled spring 19 wound around the pin 11 is interposed between the bottom surface of the receiver part 18 and the receiver piece 10 of the clutch body 8 in a spring-like manner, and the clutch body 8 is pushed inward in the radial direction. At the same time, the inner cylinder body 14 is urged outward in the radial direction.

Further, a slit 20 is formed in the outer circumference of the inner cylinder 14 in the axial direction.

Reference numeral 21 denotes an outer cylinder body which is fitted around the inner cylinder body 14 and a part of the flange 3 and the large diameter part 6 so as to be able to freely slide in the axial direction, and whose inner peripheral surface is tapered toward the tip side of the main body 1. and the inner cylinder body 14
It is tapered coupled to the

Reference numeral 22 denotes an adjustment nut for sliding the outer cylinder body 21 in the axial direction with respect to the inner cylinder body 14, and is screwed onto the outer peripheral portion of the large diameter portion 6 so as to be freely movable in the axial direction.

In addition, 23 is a lock ring equipped with a locking pawl 24, and 25 is an O that prevents the lock ring 23 from coming off.
It's a ring.

According to the embodiment configured as described above, the object 4 to be grasped, such as a tool or collet, can be mounted on the chuck in the same manner as before. That is, if the object 4 to be grasped is inserted into the chuck 5, the object 4 to be grasped can be loaded into the chuck. The grip 4 is inserted into the chassis 5 through the beveled end of the coupling piece 9 while retracting the clutch body 8 radially outward against the spring 19.
If the object to be grasped 4 is inserted in this way, the clutch body 8
The connecting piece 9 of the engaging body 12 is moved by the elastic force of the spring 19.
is engaged in the engagement recess 13 of.

Thereafter, the locking ring 23 is operated to prevent the chuck opening 5 of the gripped object 4 from being removed by the locking ball 24.

If the chuck with the object to be gripped 4 is mounted on the spindle head of a machine tool in this way and the spindle head is driven to rotate,
The object to be grasped 4 is transferred to the main body 1 via the clutch body 8 and the engaging body 12.
The machine rotates integrally with the machine, allowing work to be carried out in the same way as before.

At this time, the transmission limit torque value is determined by the elastic force of the spring 190, and when an excessive load acts on the gripped object 4IJjJJ and a torque equal to or higher than the transmission limit torque value acts on the clutch body 8, the clutch body 8 resists the elastic force of the spring 19 and retreats radially outward, and the connecting piece 9
As shown by the imaginary line in the figure, the engaging body 12 is disengaged from the engagement recess 13, and the power transmission path from the main body 1 to the object to be grasped 4 is cut off, whereby the rotation of the object to be grasped 40 is stopped. Breakage, damage, etc. of tools on the side of the object to be grasped 4 are prevented.

The transmission limit torque value can be adjusted by an extremely easy operation of screwing the adjusting nut 22 forward and backward.

That is, when the adjusting nut 22 is advanced toward the base of the main body 10, the outer cylinder 21 also moves correspondingly and slides relative to the inner cylinder 14, thereby causing the inner cylinder made of the divided body 15 to move. The cylindrical body 14 is contracted radially inward, the elastic force of the spring 19 is strengthened, and the transmission limit torque value is increased.

Conversely, if the adjustment nut 22 is moved back toward the tip of the main body 1, the elastic force of the spring 19 causes the inner cylinder 14 to move the outer cylinder 21 toward the tip of the main body 1 in the radial direction. As a result, the elastic force of the spring 19 is weakened, and the transmission limit torque value is reduced.

Note that the object to be grasped 4 can be removed from the chuck by following the procedure reverse to that for mounting.

In the embodiment, a coil-shaped spring is used, but a spring shaped like a bamboo, plate-shaped, plate-shaped, or other shapes may also be used.

In addition, in the example, the outer cylinder body and the adjustment nut were separate bodies, but
It may be integrated.

As detailed above, according to the present invention, a spring with excellent mechanical properties and durability is used as a member for biasing the clutch body, instead of using torque rubber that easily deteriorates and hardens. Since the set transmission limit torque value hardly changes, there is no fear that the transmission limit torque value will naturally increase and cause breakage or damage to the grasped object due to overload. Oil resistance, water resistance, heat resistance, etc. are also good.

Further, the transmission limit torque value can be finely and steplessly adjusted by a simple operation of sliding the outer cylinder relative to the inner cylinder by screwing the adjusting nut back and forth.

[Brief explanation of the drawing]

FIG. 1 is a vertical side view showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line A--A in FIG. 1...Chuck body, 4...Gripped object, 5...Chuck mouth, 8...Clutch body, 12...Engaging body , 13... Engagement recess, 14... Inner cylindrical body, 15... Divided body, 19... Spring, 21... Outer Cylindrical body, 22... Adjustment nut.

Claims (1)

[Scope of utility model registration request] This chuck is removably attached to the tip of a main shaft of a machine tool, and has a chuck opening formed in the axial direction on the tip side of the main body into which an object to be gripped, such as a tool or a collet, can be inserted and removed. The distal end side is removably engaged with the object to be grasped in the chuck mouth, causing the main body and the object to be rotated together, and the state of engagement with the object to be grasped is determined when a torque exceeding a set value is applied. In a chuck having a plurality of clutch bodies arranged in the circumferential direction so as to be freely movable in the radial direction, an inner cylindrical body that is freely expandable and contractable in the radial direction and whose outer circumferential surface is tapered is attached to the outer periphery of the tip side of the main body. A spring that is fitted externally to the clutch body and urges the clutch body radially inward is interposed between the inner cylinder body and the clutch body in a resilient manner, and a A tapered outer cylindrical body is fitted in a tapered manner so that it can freely slide in the axial direction, and an adjustment nut that slides this outer cylindrical body in the axial direction with respect to the inner cylindrical body is attached to the tip of the main body. A chuck characterized by being screwed onto the outer periphery so that it can move forward and backward in the axial direction.