JPH02185304A - Differential four-claw powder chuck - Google Patents

Abstract

PURPOSE:To make a variety of chucking easily with single operation by forming a jaw drive cam hole on the center line of a jaw grooves, both of which are crossed at right-angle, of a chuck body to make a jaw drive cam changeable into inward tightening type, outward tightening type, and positioning type. CONSTITUTION:A differential cam hole 2 is drilled at the center of a chuck body 1 and jaw grooves 3 are formed on the orthogonal diameter lines on its front surface in crossing shape. A jaw drive cam hole 12, in which various jaw drive cams are closely fitted rotatably, is formed on the center line of the jaw groove 3. Various types of jaw drive cams are available: inward tightening type 131 and 132, outward tightening type 133 and 134 and positioning type 135, and these are changeable. By just replacing the above various jaw drive cams or jaw drive section 13c, a variety of chucking such as four-point outward tightening, four-point inward tightening, two-point outward and two- point inward tightening, one-point positioning, etc. can be made with easy operation without replacing a chuck main body.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to irregularly shaped workpieces by four-point external tightening, four-point internal tightening, and two-point external tightening, depending on the shape and processing purpose. This product relates to a differential four-jaw power chuck that can perform various types of gripping, such as internal tightening, -point positioning gripping, two-point positioning gripping, etc., without replacing the chuck body, and with a single operation similar to a scroll chuck. be.

[Conventional technology]

Conventionally, when machining using a lathe, etc., diamond, rectangular,
Other so-called deformed materials, especially fusing materials,
When processing workpieces with poor shape accuracy, such as forged or cast materials, a single watermelon chuck must be used. Because you have to operate
In addition to requiring a high level of skill for centering, it takes a lot of time compared to scroll chucks, three-way clamping, and three-sided power chucks, which significantly impedes productivity.

Therefore, the applicant of the present application has developed a method for clamping irregularly shaped workpieces, which conventionally required the use of a single chuck, in a single operation without requiring any skill, in a time that is almost the same as that of a three-way power chuck. He invented a two-way differential centripetal two-watermelon interlocking power chuck that can perform centering and chuffing and improve productivity, and filed a patent application, which was registered as Patent No. 1440379.

[Problem to be solved by the invention]

However, the above two-way differential centripetal two-watermelon interlocking power chuck requires two-point external tightening and two-point internal tightening using four jaws in two orthogonal directions in order to grip a workpiece with a more complex shape. It is necessary to prepare a chuck body of the same model and replace it with this, and when gripping a workpiece using -point positioning or two-point positioning, a watermelon-only chuck must be used or a new jig must be installed. There was a problem in that it had to be manufactured and installed.

In view of the above problems, the present invention has developed various types of gripping methods such as four-point internal tightening, four-point external tightening, two-point external tightening, two-point internal tightening, -point positioning, two-point positioning gripping, etc. The purpose of the present invention is to provide a differential four-jaw power chuck that can be operated in a single operation similar to a scroll chuck without having to replace the chuck.

[Means to solve the problem]

In order to achieve the above object, the present invention has four jaws that are slidably held in two orthogonal jaw grooves formed on the front surface of a chuck body, and two that are opposed to each other and are slidably held in two orthogonal jaw grooves. The differential cam has a differential cam driving cam that is moved in the direction of the coaxial line by movement and is rotatable around the coaxial line, and passive slopes in mutually opposite directions that engage simultaneously with the differential cam driving cam. The drive cams are driven in opposite directions by the movement of the drive cams in the axial direction, and when one drive is restrained, the differential cam driven cam rotates and moves along the driven slope on the restrained side, thereby driving the other drive cam. a pair of differential cams that are differentially driven, a differential cam driven part that engages with each of the pair of differential cams, and a jaw drive part that engages with each of the jaws, and the chuck body In a differential four-jaw power chuck, the jaw drive cam hole is rotatably fitted into a jaw drive cam hole formed in the chuck body. It is characterized in that it is formed on each center line of the groove, and that the jaw drive cam can be converted into an external tightening type, an internal tightening type, and a positioning type.

[For production]

Therefore, if all the jaw drive cams in two orthogonal directions are replaced with external or internal clamping types, the jaw drive cams in one direction can be replaced with four-point external clamping or four-point internal clamping types.
If you replace the jaw drive cam in the other orthogonal direction with an internal tightening type, you can use a two-point external tightening two-point internal tightening type, one jaw drive cam of the positioning type, and the other three jaw drive cams of the external tightening type or If you replace it with an internal tightening type, you can use a three-point external tightening type with - point positioning or a three-point internal tightening type with one-point positioning, a positioning type for each of the jaw drive parts in two orthogonal directions, and a positioning type for the other two jaw drive parts. If you replace the cam with an external tightening type or an internal tightening type, you can drive the jaws in two orthogonal directions other than the two-point positioning two-point external tightening type, the two-point positioning two-point internal tightening type, or the above-mentioned -point positioning type. If you replace the cam with an external tightening type and an internal tightening type that are opposite to each other, you can use one-point positioning, one-point external tightening, two-point internal tightening type, --point positioning, one-point internal tightening, two-point external tightening type, or other positioning types other than the two-point positioning type mentioned above. By changing the jaw drive cams in two orthogonal directions to opposite external clamping types and internal clamping types, you can easily create a differential four-jaw power chuck with two-point positioning, one-point external tightening, and one-point internal tightening type without replacing the chuck body. It can be replaced and can appropriately grip a variety of irregularly shaped workpieces.

〔Example〕

The present invention will be described in detail below based on an illustrated embodiment.

The figure shows an example of a differential four-jaw power chuck with one-point positioning and three-point external tightening. This is a detailed view of the chuck body. The chuck body 1 has a substantially cylindrical shape, has a differential cam hole 2 bored in the center, and has a cross-shaped jaw groove 3 formed on the front surface on a perpendicular diameter line. In the figure, 4 is a front cover screwed on the front side, 5 is a back cover screwed on the rear side, and 6 is a bolt hole of the mounting port 7.

The jaw grooves 3 in two orthogonal directions have a total of 4 master jigs, 2 facing each jaw groove 3 in one direction! I-8 is slidably held. As shown in detail in FIGS. 6 to 8, the master jaw 8 has convex retaining portions 8a that engage with concave engaging portions 3a of the jaw groove 3 on both sides and engages a top jaw 9, which will be described later, on the front surface. A wave-shaped groove 8b, a T-nut groove 80 for attaching the top jaw 9, and a transverse groove-shaped passive portion 8d that engages with a jaw drive portion 13a of a jaw drive cam 13, which will be described later, are formed on the rear surface.

As shown in detail in FIGS. 9 to 11, the top jaw 9 has two mounting bolt holes 9a penetrating from the front surface to the rear surface, and engages with the wave-shaped groove 8b on the front surface of the master jaw 8 on the rear surface. A wave-shaped groove 9b is carved, and the T-nut 10 (Fig. 1) is inserted into the T-nut groove 8c of the master jaw 8, and the wave-shaped groove 9b of the top jig g9 is engaged with the wave-shaped groove 8b on the front surface of the master jaw 3-8. , a mounting pole) 11 (Fig. 1.2) is inserted into the mounting bolt hole 9a and screwed onto the T-hole 0 to be mounted on the master jaw 8.

Four jaw drive cam holes 12 are formed at concentric positions on each center line of the jaw grooves 3 in two orthogonal directions of the chuck body 1,
In each jaw drive cam hole 12, as shown in FIGS. 12 to 19,
Two types of external tightening type (Fig. 13, Fig. 16), two types of internal tightening type (
A total of five types of shaft-shaped jaw drive cams 13, 13□, 1 (Figs. 14, 17) and 1 positioning type (Fig. 19) are provided.
33, 134, and 135 are held replaceably.

First and second type jaw drive cams 13. , 13□ are an outer tightening type and an inner tightening type driven by an outer differential cam 15, which will be described later, and a radial tooth-shaped passive portion that engages with a drive groove 15c of the outer differential cam 15 on the shaft portion 13a. 13b,
When viewed from the front with the passive portion 13b facing downward, a bottle-shaped jaw driving portion 13c is formed, which is eccentric to the right in the first type (FIG. 13) and eccentric to the left in the second type (FIG. 14). The third and fourth types of jaw drive cams 13s and 134 are of an outer tightening type and an inner tightening type driven by an inner differential cam 16, which will be described later, and have a drive groove 16c of the inner differential cam 16 in the shaft portion 13a.
A radial tooth-shaped passive part 13b' that engages with the end, front view with the passive part 13b' facing down, type 3 has left eccentricity (Fig. 16), type 4 has right eccentricity (Fig. 17). ), the fifth type of jaw drive cam 13s is of a positioning type, and the shaft portion 13a has no differential cam passive part, and the jaw drive portion 13c at the end is of a positioning type. It is formed into a convex parallel dihedral shape so as to engage with the groove-shaped passive portion 8d of the master jaw a-8 and firmly hold the master jaw 8 in a fixed position.

As mentioned above, since the jaw drive cam holes 12 are located on the respective center lines of the jaw grooves 3 in two orthogonal directions, the jaw drive cams 13 . , 13□, 13. .

134 into the jaw drive cam hole 12, the jaw drive section eccentric to either the left or right is located at a symmetrical position with respect to the center line of the jaw groove 3, so that the jaw drive section is mastered! -8 will have an equal driving force.

A cylindrical outer ring differential cam 15 is rotatably held in the differential cam hole 2 at the center of the chuck body 1.
5 is the cylindrical portion 1 as shown in detail in FIGS. 20 to 22.
A flange portion 15b is formed at one end of the flange portion 15b, and a pair of drive grooves 15c that engage with the driven portions 13b of the first and second type jaw drive cams 131.13□ are provided at opposing positions on the outer periphery of the flange portion 15b; A pair of passive slopes 15d each consisting of a long hole inclined in one direction at a predetermined angle with respect to the axis C is formed at opposing positions on the outer periphery of the cylindrical portion 15a.

An inner differential cam 16 having substantially the same shape as the outer differential cam 15 is rotatably fitted into the outer differential cam 15 .
6, as shown in FIGS. 23 to 25, a flange portion 16b is formed at one end of the cylindrical portion 16a.
A pair of drive grooves 16c that engage with the driven portions 13b' of the third and fourth type jaw drive cams 133 and 134 are located at opposing positions on the outer periphery of the cylindrical portion 16a, and a pair of drive grooves 16c are provided at opposing positions on the outer periphery of the cylindrical portion 16a with respect to the axis C. A pair of passive slopes 16d formed of long holes that are inclined in the opposite direction to the passive slopes 15d of the outer ring differential cam 15 are formed.

In the illustrated example of a one-point positioning, three-point external tightening type chuck, as shown in FIG. The drive cam 13+ is connected to the other jaw drive cam hole 12 (second
5th type jaw drive cam 13. However, a third type of jaw drive cam 133 is inserted into both the jaw drive cam holes 12 and 12 (left and right in FIG. 2) of the jaw groove 3 in the other orthogonal direction, and Part 1
3b is a third type jaw drive cam 13.3b in the drive groove 15c of the outer ring differential cam 15. The passive part 13b' is the inner differential cam 1.
6 drive grooves 16c, each jaw drive cam 1
The jaw driving portions 13c at 31° 133 and 135 are engaged with the groove-shaped passive portions 8d of each master jaw 8. Note that the first to fifth types of jaw drive cams 13. ~13. A collar 14 for preventing wear is fitted onto the jaw driving portion 13c.

The contact portion between the inside of the flange portion 15b of the outer ring differential cam 15 and the chuck body 1, the flange portion 1 of the outer ring differential cam 15
Thrust needle bearings 17 and 18 are provided at the contact portions between the outside of the flange portion 16b of the inner differential cam 16 and the inside of the flange portion 16b of the inner differential cam 16, and the contact portion between the outside of the flange portion 16b of the inner differential cam 16 and the inner surface of the back cover 4, respectively. 19 is interposed to reduce frictional resistance.

In the figure, 20 is a differential cam drive cam, details of which can be found in Section 26.2.
As shown in FIG. 7, a pair of shaft-shaped differential cam drive parts 20b are formed at opposing positions on the outer periphery of an annular body in which a drawer hole 20a into which a drawbar 23 (described later) is inserted is formed. 20b is the superposed outer ring differential cam 15;
, each passive slope 15d, 1 consisting of a long hole of the inner differential cam 16.
6d at the same time and are engaged.

Note that each differential cam drive section 20b has both passive slopes 15d and 1.
Two anti-wear collars 21, 22 are fitted, each contacting 6d.

The drawbar 23 has a front part supported by a boss 4a on the inner surface of the center of the front cover 4, and a rear part that passes through the center of the back cover 5 and has an annular draw rod 24 connected to a power cylinder (not shown) at the rear end. It is attached with a nut 25, and the differential cam drive cam 20 is fitted into the front part, and the differential cam drive cam 20 is attached to the flange 2 at the front end of the drawbar 23.
3a and an annular nut 26 screwed into the drawbar 23, it is rotatable and its back and forth movement is restricted.

In the ridge configuration, when the drawbar 23 is moved in the direction of the axis C by an external power cylinder, the differential cam 2
0 also moves in the direction of axis C. Differential cam drive cam 20
The differential cam drive unit 20b has both driven slopes 15d of the outer differential cam 15 and the inner differential cam 16, which overlap in a crosswise manner because their inclinations are in opposite directions.

16d in the direction of axis C at the same time, if the rotation of both differential cams 15 and 16 is not restricted, that is, if all the top jaws 9 are idle, both differential cams 15 and
．． 16 are simultaneously rotated in opposite directions. Here, the outer differential cam 15 rotates counterclockwise in front view, and the inner differential cam 1
6 rotates clockwise in front view, the upper first type jaw drive cam 13 in FIG. 2 is driven by the outer differential cam 15 that rotates counterclockwise, and rotates clockwise. The jaw driving portion 13c eccentric to the right moves the master ji = 1-8 toward the center of the chuck. On the other hand, the fifth type jaw driving force arm 13 on the other side does not have a passive part, so it does not rotate, and the master gear that engages with it does not rotate. ! -Hold 8 in place. In addition, left and right third type jaw drive cams 13. are driven by the clockwise rotation of the inner differential cam 16 and both rotate counterclockwise,
The left eccentric jaw drive section 13c is the master jaw 8.
move toward the center of the chuck.

The workpiece is positioned by a master jaw 8 held in a fixed position, and a predetermined position is brought into contact with a top jaw 9 fixed with a bolt 11, and the workpiece is positioned by a three-way top jaw 9 that moves toward the center. When any of q-9 comes into contact with the workpiece and movement is stopped, its top position = 19
The rotation of the outer or inner differential cam 15.160 that drives the cam is restricted.

Then, the differential cam drive section 20b of the differential cam drive cam 20 is guided by the passive slope 15d or 16d of the stopped differential cam 15 or 16, and slides on the slope while rotating the differential cam drive cam 20. , the passive slope 15d of the other differential cam 15 or 16 whose rotation is not restricted accordingly.
Alternatively, push forward 16d and rotate it to move top gear I-9 that is linked to differential cam 15 or 16. When the top jaw 9 comes into contact with the workpiece, the rotation of the differential cam 15 or 16 is stopped, and the differential cam drive portion 20b of the differential cam drive cam 20 is moved between the two differential cams 15.1.
Equal driving force is applied to the passive slopes 15d and 16d of No. 6,
The top jaws 9 in three directions apply equal clamping force to the workpiece in the direction of the center of the chuck. Therefore, the workpiece is positioned at one point, and the three points are tightened with equal tightening force by the top jaws, which are differentially moved in accordance with the irregular external shape. This is done in a single operation by subtracting -23.

Figures 28 to 36 show the jaw drive cams 13+, 13z, 133. LL
, 13s. Figure 28 shows the four jaw drive cams in two orthogonal directions that are all externally tightened (type 1 133, type 3 1
3. Fig. 29 shows a general four-point external tightening type that has been converted into a four-point external tightening type.
Type 13□, Type 4 134) is a four-point internal tightening type, and Figure 30 shows two unidirectional jaw drive cams converted to an external tightening type (first type 134).
Type 13I), two-point external tightening two-point internal tightening type in which the two jaw drive cams in the other orthogonal direction are converted to an internal tightening type (Type 2 13□), Fig. 31 shows the jaw drive cam 1 in one direction and one side. One-point positioning three-point internal tightening type, with the other three jaw drive cams converted to internal tightening types (second type 13□, third type 13.), No. 32. The figure shows one jaw drive cam on one side in one direction of the positioning type (5th type 13.), and the opposite side jaw drive cam on the other side of the internal tightening type (2nd type 1).
3. One-point positioning, one-point internal tightening, two-point external tightening type, in which the two jaw drive cams on both sides in the other orthogonal directions were converted to external tightening type (Type 3 13.), Fig. 33 shows each side of the two orthogonal directions. One jaw drive cam on the side is a positioning type (5th type 13.), and one jaw drive cam on the other side opposite to this is an external tightening type (1st type 1).
31), the two jaw drive cams in the other orthogonal directions are internally tightened (
One-point positioning, one-point external tightening, two-point internal tightening type converted to 1st type 13+), Fig. 34 shows a positioning type (5th type 13.) with two jaw drive cams on each negative side in two orthogonal directions, opposed to this type. The two jaw drive cams on the other side in each of the two orthogonal directions are externally tightened (
1st type 13+, 3rd type 13. ) has been converted into a two-point positioning two-point external tightening type, Fig. 35 shows a positioning type (5th type 135) with two jaw drive cams on each negative side in two orthogonal directions, and a two-point positioning type (type 5 135) opposite to this on the other side in each orthogonal direction. Two-point positioning, two-point internal tightening type in which the two jaw drive cams of the above are converted to internal tightening types (2nd type 13□, 4th type 134), Fig. 36 shows the jaw drive cams 2 on each negative side in two orthogonal directions. The jaw drive cams on the other sides in the two orthogonal directions opposite to the jaw drive cams are formed using an outer tightening die (first type 131) and an inner tightening die (fourth type 13.), which are opposite to each other.
This shows a two-point positioning, one-point external tightening, one-point internal tightening type chuck converted to Type 134).

The means for converting the above-mentioned jaw drive cams into external clamping type, internal clamping type, and positioning type is to replace each jaw driving cam forming the external clamping type, internal clamping type, and positioning type jaw drive part with a jaw driving cam hole. However, FIG. 37 shows means for converting the jaw drive cam into an external clamping type, internal clamping type, or positioning type jaw driving cam by replacing the jaw drive unit with a common shaft part.

That is, the jaw drive cam 13' is formed separately from the shaft section 13a' and the jaw drive section 130', and the shaft section 13a' has a passive section 13b that engages with the drive groove 15c of the outer differential cam 15. There are two types, one in which a passive part 13b' that engages with the drive groove 160 of the inner differential cam 16 is formed, and a square hole 13d is formed in the center of the end.

The jaw driving portion 130' is formed through the square hole 13d of the shaft portion 13a'.
There are two types: one in which a bottle-shaped jaw drive part 13c+ is eccentrically formed integrally with the square shaft-like insertion part 13e inserted into the square shaft-shaped insertion part 13e, and the other in which a neutral pin-shaped jaw drive part 13c2 is not eccentric in the same insertion part 13e.
There are two types: one formed in one piece and the other.

Then, if the jaw driving part 13ct eccentric to the shaft part 13a' having the driven part 13b that engages with the driving groove 15c of the outer ring differential cam 15 is inserted with the driven part 13b facing down and eccentric to the right in front view, The jaw drive cam 131 is of type 1 (outer tightening type), and if it is reversed and inserted eccentrically to the left, it will engage the jaw drive portion 138 of the second type (inner tightening type) and the drive groove 16c of the inner differential cam 16. If the jaw drive part 13c1 eccentric to the shaft part 13a' having the mating driven part 13b' is inserted with the driven part 13b' facing down and the front sight eccentric, the third type (external tightening type) jaw drive cam can be obtained. 13. Then,
If it is reversed and inserted eccentrically to the right, the fourth type (inner tightening type) jaw drive cam 13. If a neutral jaw drive part 13c2 that is not eccentric is inserted into the shaft part 13a' having a passive part 13b or 13b' that engages with either the drive groove 15c or 16c of the outer ring or inner ring differential cam, the above-mentioned There are 5 types (positioning type) of jaw drive cams 13s. This jaw drive cam 13s is driven by the outer ring or inner ring differential cam 15 or 16, and the shaft portion 13a' rotates, but the jaw drive portion 13cz is not eccentric and therefore remains neutral.

Therefore, if all 10 types of chuck conversion were performed by replacing the jaw drive cams, two of each of the five types of jaw drive cams would be required, whereas if conversion was performed by replacing the jaw drive parts, the shaft The number of jaw drive parts is 2 types, 2 types, and the jaw drive parts are 6 types, 4 eccentric types and 2 neutral types.

FIG. 38 shows the differential cam drive section 20 of the differential cam drive cam 20.
d are provided in two pairs in three orthogonal diametrical directions, and correspondingly, passive slopes 15d and 16 of the outer differential cam 15 and the inner differential cam 16 are provided.
This figure shows an embodiment in which two pairs of d are provided on two orthogonal diameter lines. By increasing the number of pairs of differential cam drive units 20d in this manner, the strength of the chuck can be increased.

〔Effect of the invention〕

As described in detail above, the present invention has four jaws that are slidably held in two orthogonal jaw grooves formed on the front surface of the chuck body, and that are slidably held in the jaw grooves in two orthogonal directions. While being moved in the coaxial direction by movement,
It has a differential cam drive cam that is rotatable around the same axis, and passive slopes that engage simultaneously with the differential cam drive cam and are opposite to each other, and that are reversed by the movement of the differential cam drive cam in the axial direction. A pair of differential cams that are driven in a direction, and when one drive is restrained, the other is differentially driven by the driven cam rotating and moving along the driven slope on the restrained side. , a differential cam driven part that engages with each of the pair of differential cams, and a jaw drive part that engages with each of the jaws, and is rotatable in a jaw drive cam hole formed in the chuck body. In a differential four-jaw power chuck configured with a jaw drive cam that is freely fitted, the jaw drive cam holes are formed on each center line of the jaw groove in two orthogonal directions of the chuck body, and the jaw The drive cam can be converted to an external tightening type, an internal tightening type, or a positioning type, so you can perform four-point internal tightening or four-point external tightening by simply replacing the jaw drive cam or its jaw drive part without replacing the chuck body. Of course, it can be converted to a differential four-jaw power chuck that can perform various types of gripping such as two-point external tightening, two-point internal tightening, -point positioning, and two-point positioning gripping.

Therefore, irregularly shaped workpieces can be gripped using the most appropriate gripping method depending on the shape, and this gripping can be done with a single operation similar to a conventional scroll chuck, so even non-skilled workers can increase productivity. can be significantly improved.

Since only one chuck is required as a pace, there are great economic effects such as a significant reduction in equipment costs.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIGS. 1 and 2 are general views of the power chuck according to the present invention, FIG. 1 is a folded cross-sectional view thereof, and FIG. 2 is a half-sectional front view thereof. , Figures 3 to 5 are detailed views of the chuck body, and Figure 3 is its side sectional view.
Figure 4 is a half front view of the master jaw, Figure 5 is a cross-sectional view of its jaw groove, Figures 6 to 8 are detailed views of the master jaw, Figure 6 is its side view, and Figure 7 is its side view. A plan view, FIG. 8 is a rear view, and FIGS. 9 to 11 are detailed views of the top jaw.
Fig. 9 is a side view thereof, Fig. 10 is a plan view thereof, Fig. 11 is a front view thereof, Fig. 12 is a side view of the first and second type jaw drive cams, and Fig. 13 is a side view of the first type jaw drive cam. 14 is a front view of the second type of jaw driving cam, FIG. 15 is a side view of the third and fourth types of jaw driving cams, and FIG. 16 is a front view of the third type of jaw driving cam. FIG. 17 is a front view of the fourth type of jaw driving cam, FIG. 18 is a side view of the fifth type of jaw driving cam, and FIG. 19 is a front view of the fifth type of jaw driving cam. The front view, Figures 20 to 22 are detailed views of the outer ring differential cam, Figure 20 is its rear view, Figure 21 is a cross-sectional view taken along line A-A in Figure 20, and Figure 22 is its cross-sectional view. 23 to 25 are detailed views of the inner differential cam, FIG. 23 is a rear view thereof, FIG. 24 is a sectional view taken along the line B-B in FIG. 23, and FIG. 25 is a developed view of the passive slope. The figure is a developed view of the passive slope, and Figures 26 and 27 are detailed views of the differential cam drive cam.
Figure 26 is its front view, Figure 27 is its side view, and Figure 28 is its front view.
Figures to Figures 36 show the conversion modes of various chucks. Figure 28 is a four-point external tightening type, Figure 29 is a four-point internal tightening type, and Figure 30 is a two-point external tightening type and a two-point internal tightening type. , Fig. 31 shows one-point positioning, three-point internal tightening type, Fig. 32 shows one-point positioning, one-point internal tightening, two-point external tightening type, Fig. 33 shows one-point positioning, one-point external tightening, two-point internal tightening type, and Fig. 34 shows two-point positioning. Two-point external tightening type,
FIG. 35 is a two-point positioning, two-point internal tightening type chuck, FIG. 36 is a two-point positioning, one-point external tightening, one-point internal tightening type chuck, and FIG. 37 is a perspective view showing another embodiment of the jaw drive cam conversion means. FIG. 38 is a sectional view showing another embodiment of the differential cam drive cam. 1... Chuck body, 3... Jaw groove, 8...
Master jaw 9...Top jaw, 12...Jaw drive cam hole, 13. , 13□...Outer tightening type jaw drive cam, 13□, 134...Inner tightening type jaw drive cam, 13. ...Positioning type jaw drive cam, 13'
... Jaw drive unit replaceable jaw drive cam, 13a,
13a' - shaft portion, 13b. 13b'... Passive part, 13c, 13c'... Jaw drive part, 15... Outer ring differential cam, 15d... Passive slope, 16... Inner ring differential cam, 16d... Passive slope , 20...Differential cam drive cam, 23...Drawer Figure 1 Figure 1 Figure ■ Figure 5C

Claims (4)

[Claims] (1) Four jaws are slidably held in two orthogonal jaw grooves formed on the front surface of the chuck body, and move in the coaxial direction by the axial movement of the drawbar. and a differential cam drive cam rotatable about the same axis, and passive slopes in mutually opposite directions that engage simultaneously with the differential cam drive cam, and the differential cam drive cam is rotated in the axial direction. A pair of differential cams that are driven in opposite directions by movement, and when one drive is restrained, the other is differentially driven by the driven cam rotating and moving along the passive slope on the restrained side. A jaw drive cam formed on a chuck body, including a differential cam, a differential cam driven part that engages with each of the pair of differential cams, and a jaw drive part that engages with each of the jaws. In a differential four-jaw power chuck configured with a jaw drive cam rotatably fitted in the hole, the jaw drive cam hole is formed on each center line of the jaw groove in two orthogonal directions of the chuck body. At the same time, the jaw drive cam can be of external tightening type, internal tightening type,
A differential four-jaw power chuck that can be converted into a positioning type. (2) The means for converting the jaw drive cam into an outer tightening type, an inner tightening type, and a positioning type is a means for converting each jaw drive cam into an outer tightening type, an inner tightening type, and a positioning type jaw drive portion, respectively. The differential four-jaw power chuck according to claim 1, wherein the differential four-jaw power chuck is adapted to be replaced with a hole. (3) The means for converting the jaw driving cam into an external clamping type, internal clamping type, or positioning type is such that an external clamping type, internal clamping type, or positioning type jaw drive section is replaced with a jaw driving cam. The differential four-jaw power chuck according to claim (1). (4) Claim (1) or (2) characterized in that a plurality of differential cam drive portions of the differential cam drive cam are provided, and a plurality of passive slopes of each differential cam are provided correspondingly. Or the differential four-jaw power chuck described in (3).