JP2000135608A - Chuck capable of changing chuck form between two-jaw chuck and three-jaw chuck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate an adjustment of rotational balance between chucks, and change a chuck form between the chucks by setting mass of the respective master jaws so that unbalance is not caused in centrifugal force generated by rotation of the chucks between the respective master jaws. SOLUTION: Rotational balance of a chuck 1 is kept by setting the mass ratio of the respective master jaws 3a to 3d to (3a:3b:3c:3d=2:1:1:1) so that unbalance is not caused in centrifugal force generated by rotation of the chuck 1 between the respective master jaws 3a to 3d regardless of the distance when the respective master jaws 3a to 3d exist at an equal distance from the rotational center of a chuck 1. Thus even if a distance (r) from the chuck center of the master jaws 3a to 3d moves since a jaw 5 is abraded or a work gripping position is changed, the rotational balance of the chuck 1 is always kept in the four master jaws 3a to 3d. Rotational balance adjusting work of the chuck 1 can be obviated without arranging a balance adjusting tap hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a two-jaw chuck and a three-jaw chuck.
The present invention relates to a chuck capable of changing a chuck type between a jaw chuck and a jaw chuck.

[0002]

2. Description of the Related Art Conventionally, a chuck 100 capable of changing a chuck type between a two-jaw chuck and a three-jaw chuck is shown in FIG.
As shown in FIGS. 6 to 6, three master jaws 102 to 104 are provided so as to move in the radial direction of the chuck body 101 at equal intervals in the circumferential direction of the chuck body 101, and two master jaws 103, 1
04, the adjacent master jaw 103,
A master jaw 105 is provided at a central position of 104 so as to move in the radial direction, and four master jaws 102 to 105 are provided.
Is moved by one wedge plunger. The top jaw 10 depends on the shapes of the works W1 and W2.
By reassembling 6, sometimes a two-jaw chuck (Fig. 5)
It is known that at some point it is used as a three-jaw chuck (FIG. 6).

[0003]

SUMMARY OF THE INVENTION The conventional chuck 1 described above.
In the case of 00, the four master jaws 102 to 105 are unevenly arranged on the circumference of the chuck 100 with three on one side and one on the other side with respect to the center of rotation of the chuck 100. And the like, resulting in an unbalanced state. Therefore, in the initial stage of chuck shipment, the workpiece grasping position is set to the middle of the master jaw moving distance, and in that state, the chuck body 101 is provided with the tap hole 107 for balance adjustment, so that the rotation balance of the chuck 100 is adjusted. I have. Furthermore, nail 1
When the master jaws 102 to 105 move from the work grasping position at the initial stage of chuck shipment, the chuck body 1
For example, the rotation balance of the chuck 100 is adjusted by stuffing an object such as lead into the balance adjustment tap hole 107 provided in the device 01 or removing the object once attached.

However, each time the claws 106 are worn or the outer dimensions of the work are changed, the master jaws 102 to 105 are changed.
The gripping position of the workpiece changes, so that each time the lead or the like is packed into the tap hole 107 for balance adjustment,
The rotation balance of 00 had to be adjusted, which could greatly affect the setup time. Therefore,
An object of the present invention is to provide a chuck type between a two-jaw chuck and a three-jaw chuck which does not need to adjust the rotational balance of the chuck even when the gripping position is changed due to wear of the jaws or different workpieces to be machined. To provide a chuck capable of changing the pressure.

[0005]

According to the present invention, three master jaws are provided at equal intervals in the circumferential direction of the chuck body so as to move in the radial direction of the chuck body. A master jaw is provided at one position between two master jaws so as to move in the radial direction at the center position of adjacent master jaws, and a top jaw is attached to the three equally spaced master jaws.
A chuck capable of changing a chuck type between a jaw chuck, a master jaw provided between the two adjacent master jaws, and a two-jaw chuck having a top jaw attached to a master jaw at a position 180 degrees opposite to the master jaw. In the above, when each master jaw is at the same distance from the chuck rotation center, regardless of the distance, the mass of each master jaw is set so that the centrifugal force generated by the chuck rotation does not become unbalanced. .

[0006] Of the three master jaws having a circumferential interval of 60 ° from each other, the mass of the master jaws arranged on both sides of the master jaw arranged at the center position is the same, and the mass of the master jaws arranged at the center position is determined by Master Jaw and 18
The mass of the master jaw at the position facing 0 degrees was increased.

More specifically, the masses of three master jaws having circumferential intervals of 60 ° are all the same, and the master jaw at the center position among the three master jaws is 18 masses.
The mass of the master jaw at the position facing 0 degrees is
Twice the mass of one master jaw. Further, the master jaw whose mass is doubled is doubled in mass by making it larger than other master jaws.

[0008]

Embodiments of the present invention will be described with reference to the drawings. 1-4, a chuck 1 capable of changing a chuck type between a two-jaw chuck and a three-jaw chuck.
Are the four master jaws 3a to 3d on the chuck body 2.
And a wedge plunger 4 capable of engaging with the master jaws 3a to 3d and simultaneously moving the master jaws 3a to 3d in the radial direction of the chuck 1. Then, the top jaw 5 is attached to two or three master jaws (3a, 3c) and (3a, 3b, 3d) depending on the shape of the work. At the center of the chuck body 2, a chuck center hole 2a extending in the front-back direction in the axial direction is provided, and the wedge plunger 4 is guided to be movable in the axial direction. A pilot bush 6 fixed to the front surface of the chuck body 2 with a screw member 9 is loosely fitted in the wedge plunger center hole 4a. A draw screw 7 that moves in the front-rear direction by a drive source (not shown) is fixed to the rear end face 4b of the wedge plunger. The draw screw 7 moves the top jaw 5 to the work grasping position via the wedge plunger 4.

In the circumferential direction of the chuck body 2, the above 4
Jaw guide groove 8 holding two master jaws 3a to 3d
a to 8d are formed so as to open radially outward from the center side of the chuck 1. The three jaw guide grooves 8a, 8b, 8d are provided at equal intervals (120 ° intervals) in the circumferential direction of the chuck body 2. The remaining jaw guide grooves 8c are provided at one central position between the two adjacent jaw guide grooves 8b and 8d at the above-mentioned 120 ° intervals at circumferential intervals of 60 ° from the jaw guide grooves 8b and 8d, respectively. It is. Therefore, four jaw guide grooves 8a
8d are unevenly arranged on the circumference of the chuck 1. In the unevenly arranged jaw guide grooves 8a to 8d,
Master jaw 1 of the same shape and mass as in the prior art
When the chuck 1 is rotated with 02 to 105 attached, the rotational balance of the chuck 1 is lost due to the centrifugal force applied to each master jaw 102 to 105. Therefore, the conventional chuck 100 must be provided with a tap hole 107 for balance adjustment.

However, when the centrifugal force applied to the master jaws 3a to 3d is determined, the mass of the master jaws 3a to 3d is represented by m, and the master jaws 3a to 3d are measured from the rotation center of the chuck 1.
The distance to 3d centroid and r, assuming that rotates the chuck 1 at a rotational angular velocity omega, the master jaw 3a~3d centrifugal force Mromega ² occurs. X-axis, Y-axis for each centrifugal force
When the master jaws 3a to 3d shown in FIG. 1 are disposed on the upper and lower sides of the master jaws 3a to 3d shown in FIG. 0 in the X-axis direction of the master jaw 3a, + mr in the Y-axis direction
centrifugal force is decomposed allocated to ω ^2. In the lower three master jaws 3b to 3d, + (mrω ² × COS30 °) in the X-axis direction of the master jaw 3b and − (mrω in the Y-axis direction).
² × SIN30 °), 0, Y in the X-axis direction of master jaw 3c
Axially -mrω ^2, the X-axis direction of the master jaw ^{3d - (mrω 2 × COS30 °} ), the Y-axis direction - (mrω ² ×
The centrifugal force is distributed to SIN30 °).

From the above, it can be seen that the master jaws 3a to 3d
Since the combined centrifugal force generated and resolved in the X-axis direction becomes zero when combined, it is considered that the upper side and the lower side are balanced. For the Y-axis direction in the degradation apportioned centrifugal force, combined with the centrifugal force + mrω ² the synthesis of the centrifugal force generated in the lower three master jaws 3b~3d occurs -2Mromega ² becomes, on the upper side of the master jaw 3a However, since it does not become zero, the centrifugal force generated by the rotation of the chuck 1 is unbalanced. So, the upper master jaw 3
The centrifugal force generated and resolved in the Y-axis direction is 2 mr
If ω ² , it is considered that the rotation of the chuck 1 can be balanced only by the four master jaws 3 a to 3 d, so that the master jaw 3 a attached to the jaw guide groove 8 a is
Master jaw 3 to be attached to other jaw guide grooves 8b to 8d
It is formed large so as to be twice as large as b to 3d.

Therefore, when each of the master jaws 3a to 3d is at the same distance from the rotation center of the chuck 1, the chuck 1 is attached to each of the master jaws 3a to 3d regardless of the distance.
The ratio of the mass of each master jaw 3a to 3d is set to 3a: 3 so that the centrifugal force generated by the rotation of
If b: 3c: 3d = 2: 1: 1: 1 is set and the rotation of the chuck 1 is balanced, the claws 5 will be worn or the workpiece grasping position will be changed, and the master jaws 3a to 3d will be displaced from the chuck center. Even if the distance r moves, four master jaws 3
Since the rotational balance of the chuck 1 is always maintained in a to 3d, there is no need to provide the tap hole 107 for balance adjustment, and the work of adjusting the rotational balance of the chuck 1 can be unnecessary. Also, as in the present embodiment, of the four master jaws, three master jaws 3b, 3c, and 3d whose circumferential intervals are 60 degrees from each other have the same mass, and only the master jaw 3a has the other masters. When the mass is twice the mass of the jaw, there are only two types of master jaws, and there is no need to have many types of master jaws.

It is to be noted that adjacent circumferential intervals are set at 60 ° from each other.
Master jaws 3b, 3
c and 3d, the master jaws 3b and 3d on both sides of the center jaw 3c used when functioning as a two-jaw chuck have the same mass, and the master jaws 3b and 3d at the center positions of these master jaws 3b and 3d If the mass of the master jaw 3a at a position 180 degrees opposite to the master jaw 3c is set to be larger than the mass of the master jaw 3c and the balance is maintained so that the above-described centrifugal force is balanced in the Y-axis direction, the chuck 1 will
Since the rotation balance of the master jaws 3a to 3d can be maintained, for example, the mass ratio of the master jaws 3a to 3d is set to 3a: 3.
b: 3c: 3d = 1.5: 1: 0.5: 1 In short, when each master jaw is at an equal distance from the chuck rotation center, regardless of the distance, each master jaw is rotated by chuck rotation. What is necessary is just to set the mass of each master jaw so that imbalance does not occur due to the generated centrifugal force. Further, in the present embodiment, the shape of the master jaw is increased in order to increase the mass of the master jaw. However, the mass of the master jaw may be changed by changing the material of the master jaw.

[0014]

As described above, the present invention relates to a chuck capable of changing the type of chuck between a two-jaw chuck and a three-jaw chuck, and when each master jaw is at an equal distance from the chuck rotation center, Instead, the mass of each master jaw was set so that the centrifugal force generated during rotation of the chuck did not cause imbalance in each master jaw.
The rotation balance of the chuck can be maintained by the four master jaws, so that even when the gripping position of the master jaw from the center of rotation of the chuck is moved due to a change in the work shape or the like, it is not necessary to adjust the rotation balance of the chuck. If three master jaws have the same mass and only one has twice the mass, the type of master jaw is 2
Since a chuck that achieves the above effects can be obtained with only the type,
Only one kind of parts is added, which is preferable in manufacturing management.

[Brief description of the drawings]

FIG. 1 shows a chuck according to the present invention which does not require adjustment of the rotation balance of the chuck.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged sectional view taken along line III-III of FIG. 1;

FIG. 4 is an enlarged sectional view taken along the line IV-IV of FIG. 1;

FIG. 5 is a diagram showing a conventional chuck in a two-jaw chuck type.

FIG. 6 is a view showing a conventional chuck having a three-jaw chuck type.

[Explanation of symbols]

 1 chuck 2 chuck body 3a to 3d master jaw 5 top jaw

Claims (4)

[Claims] 1. The chuck body is provided at equal intervals in the circumferential direction of the chuck body.
One master jaw is provided so as to move in the radial direction of the chuck body, and the master jaw is moved radially to the center position of the adjacent master jaws at one position between two adjacent master jaws. And a three-jaw chuck having a top jaw attached to the three equally spaced master jaws, a master jaw provided between the two adjacent master jaws, and a top jaw located at a position 180 degrees opposite to the master jaw. In a chuck capable of changing the chuck type between a two-jaw chuck to which a jaw is attached, when each master jaw is at an equal distance from the chuck rotation center, a centrifugal force generated by chuck rotation is exerted on each master jaw regardless of the distance. Characterized in that the mass of each master jaw is set so that no imbalance occurs in Chuck capable of changing the chuck format between the chuck and the 3-jaw chuck. 2. The mass of the master jaws arranged on both sides of the master jaw arranged at the center position among the three master jaws arranged at a circumferential distance of 60 ° from each other is equal to the mass of the master jaw arranged at the center position. , Its master jaw and 1
2. The two-jaw chuck according to claim 1, wherein the mass of the master jaw located at a position facing 80 degrees is increased.
Chuck that can change the chuck type with the jaw chuck. 3. A master jaw located at a position 180 degrees opposite to a master jaw located at a center position among all three master jaws having the same mass in a circumferential interval of 60 ° with respect to each other. 3. The mass of the three master jaws is twice as large as the mass of the other three master jaws.
A chuck capable of changing a chuck type between the described two-jaw chuck and the three-jaw chuck. 4. A two-jaw chuck and a three-jaw chuck according to claim 3, wherein the mass of the master jaw whose mass is doubled is doubled by making it larger than other master jaws. Can change the chuck.