JPH0739459Y2 - Cam switching device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a cam switching device for a cam drive unit used in, for example, a transfer device.

2. Description of the Related Art A conventional cam switching device is, for example, as shown in FIG.
A plurality of cams 1 are mounted on a cam shaft 101 that is rotationally driven by a drive device.
02 to 104 are fixed, and a sliding shaft 106 is movably provided in an axial direction on a lever 105 rotatably supported by a support shaft 100 parallel to the cam shaft 101, and a bearing 107 is attached to the sliding shaft 106. Each cam through
A cam follower 108 that can abut on 102 to 104 is rotatably provided, and both ends of the sliding shaft 106 have cylinder holes 109A, 10A in the axial direction.
9B is formed, and piston rods 110A and 110B are fitted in and out of the cylinder holes 109A and 109B, respectively, and the tip end portions of these piston rods 110A and 110B are connected to the lever 105 via the support members 111A and 111B. Configured.

Further, in the case of FIG. 8, the fixed shaft 122 fixed to the lever 121 is provided with the sliding cylinder 123 which is movable in the axial direction via the key,
Cylinder hole 1 in the axial direction opposite to each other in this sliding cylinder 123
24A and 124B are formed, and each cylinder hole 124A and 124B
Inside, there is a piston rod 125 whose tip is fixed to the lever 121.
A and 125B are fitted together, a cam follower 127 is fitted onto the sliding cylinder 123 via a bearing 126, and the cam follower 127 can be brought into contact with the cams 128A and 128B.

Problems to be Solved by the Invention According to the former conventional example, since the supporting members 111A and 111B project on both sides of the cam follower 108, a wide occupied space is required, and there is a problem that it is difficult to incorporate into the device and layout is difficult. It was

Further, according to the latter conventional example, since the cam follower 127 is arranged on the fixed shaft 122 via the sliding cylinder 123 having the cylinder holes 124A and 124B and the bearing 126, the outer diameter of the cam follower 127 becomes large. However, there was a problem that the cam could not follow a large change and the whole size became large.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cam switching device which solves the above problems and can reduce the outer diameter of the cam follower and the lateral width of the mounting portion and avoid the size increase of the device.

Means for Solving the Problems In order to solve the above problems, a lever having a cam shaft having a plurality of cams and a cam follower that is swingably supported about an axis parallel to the cam shaft and abuts against the cam In the cam switching device including the rotary shaft, the first means is rotatably provided on the lever with a rotary shaft parallel to the cam shaft via a bearing, and the cam follower is externally slidably fitted in the axial direction. While projecting a piston portion over the entire outer peripheral surface of the, the inner peripheral surface of the shaft hole of the cam follower, to form an annular cylinder hole that is slidably fitted to the piston portion in the axial direction, The rotary shaft is provided with hydraulic pressure supply holes for supplying and discharging pressure oil to oil chambers formed on both sides of the piston portion.

In the second means, a rotary shaft parallel to the cam shaft is rotatably provided on the lever via a bearing, and a cam follower is slidably fitted on the rotary shaft via a shaft hole in the axial direction to allow the rotary shaft to rotate. A piston part is provided so as to extend over the entire circumferential direction on one of the outer peripheral surface of the shaft and the shaft hole of the cam follower, and a cylinder hole is formed on the other part of the piston part so as to be slidably fitted on the piston part in the axial direction. The rotary shaft is provided with oil pressure supply holes for supplying and discharging pressure oil to oil chambers formed on both sides of the portion.

Further, the third means is that an eccentric shaft parallel to the cam shaft is rotatably provided on the lever, and cam followers respectively facing the cam are rotatably provided via bearings at positions of different eccentricity on the eccentric shaft. A rotating means for rotating the shaft is provided.

Action According to the first means, the pressure follower is supplied to the oil chamber of the cylinder hole to slide the piston rod, and the slide cylinder is slid in the axial direction through the groove portion, so that the cam follower corresponds to each cam. The cam acting on the lever can be switched by reciprocating between the positions.

According to the second means, by supplying pressure oil from the hydraulic pressure supply hole to the oil chamber of the cylinder chamber formed between the rotary shaft and the shaft hole of the cam follower, the cam follower is directly moved along the axis of the rotary shaft. By sliding the cam follower back and forth between the corresponding positions of the cams, the cams acting on the levers can be switched. Therefore, no bearing is required between the rotary shaft and the cam follower, and the diameter of the cam follower can be reduced.

According to the third means, it is possible to rotate the eccentric shaft by the rotating means to move the cam follower close to and away from the cam, and drive the lever by the cam follower and the cam that are closest to each other, and the desired cam can be arbitrarily set. You can choose.

Embodiment An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 6, this cam switching device is arranged in a drive unit 1 of a transfer device for sequentially transferring a work to a die in a transfer press, for example, and the die is changed every time the work is changed. In addition, the stroke of the feed bar 9 for progressively feeding the work is also changed correspondingly. The drive unit main body 2 is provided with a cam shaft 3 which is rotationally driven by a drive source in a horizontal direction orthogonal to the work transfer direction, and a plurality of (two in the drawing) cams 4A and 4B are attached to the cam shaft 3. Has been. Further, the drive unit main body 2 is provided with a swingable feed lever 6 having an intermediate portion supported by a support shaft 5 parallel to the cam shaft 3, and a restraining cylinder (not shown) is provided at a lower end portion of the feed lever 6. ), A cam follower 7 (7a, 7b) which is brought into contact with either of the cams 4A, 4B is provided. A feed bar 9 is connected to the upper end of the feed lever 6 via a feed carriage 8, and a work suction tool is attached to the feed bar 9 via a cross bar.

First, the first embodiment will be described with reference to FIGS. 1 and 2.

A fixed shaft 11 is arranged between the lever frames 12 of the feed lever 6 in parallel with the cam shaft 3, and a slide cylinder 13 slidable in the axial direction is fitted onto the fixed shaft 11. This slide tube
13 is divided into two in the axial direction, and cams 4A and 4B are mounted via bearings 14.
A cam follower 7 that can come into contact with is rotatably supported.

Reference numeral 15 is a cylinder hole formed in the axial direction over the entire length in the vicinity of the outer peripheral surface of the fixed shaft 11, both ends of which are closed by plugs 17A and 17B having oil supply ports 16A and 16B, and a groove portion 15a which opens to the outer peripheral surface. And left and right oil chambers 15b and 15c partitioned by a sealing material on both sides of the groove 15a are formed. And
A slidable piston rod 18 is fitted in the cylinder hole 15 so as to extend between the oil chambers 15b and 15c. Further, the groove 15 is formed in the middle of the piston rod 18.
Connecting member 1 connected to one end of the slide cylinder 13 via a
9 is attached.

Therefore, after releasing the feed lever 6 from the restraint cylinder,
By supplying hydraulic pressure from the oil supply port 16A into the oil chamber 15b and discharging the oil from the oil chamber 15B, the piston rod 16
Can be slid in the direction of arrow A to slide the slide cylinder 13 via the connecting member 19, and the cam follower 7 can be moved from the contact position of the cam 4A to the contact position of the cam 4B.
On the contrary, by supplying the pressure oil to the oil chamber 15c and discharging the oil from the oil chamber 15b, the cam follower 7 can be moved in the arrow B direction from the contact position of the cam 4B to the contact position of the cam 4A.

According to the first embodiment described above, since the slide cylinder of the cam follower 7 is incorporated in the fixed shaft 11, the cam follower 7
The diameter can be reduced and the whole can be made extremely compact.

Next, a second embodiment will be described with reference to FIG.

This is one in which a cylinder mechanism, which is an example of a slide unit of a cam follower, is provided between a rotary shaft and a cam follower.

That is, on the rotary shaft 51 rotatably supported by the lever frame 41 of the feed lever 6 via the bearing 43, an annular piston portion 51a is formed in the central portion so as to project over the entire circumference.
At the shaft hole 50 portion of the cam follower 7, there is provided a cylindrical cylinder portion 52 in which a cylinder hole 51c is formed which is slidably fitted onto the piston portion 51a in the axial direction. And the cylinder hole
Both end portions of 51c are closed by annular closing portions 52a, 52b that are in sliding contact with the shaft portion 51b of the rotary shaft 51, and annular oil chambers 53A, 53B are formed around the shaft portion 51b on both sides of the piston portion 51a. There is. Further, hydraulic supply holes 54A, 54B, one end of which is connected to an external hydraulic pipe via a rotary joint 48, are bored in the rotary shaft 51 and are opened in a shaft portion 51b near the piston portion 51a, and each oil chamber 53A,
It is connected to 53B.

In the above structure, by supplying the pressure oil from the hydraulic pressure supply hole 54A to the oil chamber 53A and discharging the oil from the oil chamber 53B, the cam follower 7 is slid in the arrow G direction to move from the contact position of the cam 4A to the cam. The cams 4A and 4B acting on the lever 6 can be switched by moving to the contact position of 4B. vice versa,
While supplying pressure oil to the oil chamber 53B from the hydraulic pressure supply hole 54B,
By discharging oil from the oil chamber 53A, the cam follower 7
Can be slid in the direction of arrow H to switch from cam 4B to cam 4A.

According to the second embodiment, since the cylinder mechanism is formed between the rotary shaft 51 and the cam follower 7, the diameter of the cam follower 7 can be further reduced.

Next, a third embodiment will be described with reference to FIGS.

An eccentric shaft 63 parallel to the cam shaft 3 is rotatably disposed between the lever frames 61 of the feed lever 6 via a bush 62, and the eccentric shaft 63 is coaxial with a portion supported by the bush 62. The concentric part 63a on the center is formed at the position corresponding to the cam 4A, and the eccentric part 63b which is eccentric from the concentric part 63b by α is formed at the position corresponding to the cam 4B. A first cam follower 7a facing the cam 4A via a bearing 64A is rotatably fitted on the concentric portion 63a, and a second cam follower 7b facing the cam 4B via a bearing 64B is fitted on the eccentric portion 63b. It is rotatably fitted on the outside.

A rack and pinion mechanism, which is an example of a rotating unit, is provided on one end side of the eccentric shaft 63, and the eccentric shaft 63 can be reciprocally rotated within a range of 180 degrees. That is, the pinion 65 is fixed to one end of the eccentric shaft 63, and the rack shaft 66 meshing with the pinion 65 is provided on the outer surface of the lever frame 61 as a guide member.
It is arranged so as to be reciprocally movable in the length direction via 67.
The piston rod 68a of the switching cylinder 68 attached to the lever frame 61 is connected to the rack shaft 66, and the eccentric shaft 63 is rotationally driven.

In the above structure, as shown in FIG. 4, the switching cylinder 68 is in the contracted position and the second cam follower 7b is located on the eccentric portion 63b.
In the state in which is retracted, the first cam follower 7a in the concentric portion 63a contacts the cam 4A and the feed lever 6 is driven.

From this state, the switching cylinder 68 is extended and the rack shaft 66
By moving the eccentric shaft 63 through the pinion 65 by 180 degrees, the second cam follower 7b is rotated as shown in FIG.
The cam acting on the feed lever 6 can be switched from the cam 4A to the cam 4B by projecting the first cam follower 7a to the cam 4B side and bringing them into contact with each other. On the contrary, by contracting the switching cylinder 68, the cam 4B can be returned to the cam 4A.

According to the third embodiment, the eccentric shaft 63 is utilized to utilize the eccentric shaft 63.
By rotating the cam follower 180 degrees, the cam follower 7b can be moved back and forth by a distance corresponding to twice the amount of eccentricity, and the contacting cam follower 7 can be arbitrarily selected to switch the cams 4A and 4B. Therefore, cam followers 7a, 7
There is no need to install a cylinder mechanism in b, the size can be reduced with an extremely simple structure, and since the cam followers 7a and 7b and the shaft with cam follower cannot be slid, the power required for switching is also small. Good.

Although the rack and pinion mechanism is used as the rotating means of the eccentric shaft 63, a link mechanism, a motor, or the like can be used.

Advantageous Effects of Invention As described above, according to the first means of the present invention, the cylinder mechanism for switching drive is built in the fixed cylinder that supports the cam follower via the slide cylinder, and the groove portion communicating with the cylinder hole is provided. Since the output of the cylinder mechanism is taken out to the outer peripheral surface of the fixed shaft by connecting the piston rod and the slide cylinder via the, the width of the cam follower mounting portion including the fixed shaft can be reduced. In addition, only the cam follower and slide cylinder are required to slide for switching, and only a small driving force is required. Therefore, the inner diameter of the cylinder can be reduced, and the diameter of the fixed shaft and the diameter of the cam follower can be reduced. .

Further, according to the second means, since the cylinder mechanism including the piston portion and the cylinder hole is provided in the outer peripheral surface of the rotary shaft and the shaft hole of the cam follower, the output can be directly taken out from the cylinder mechanism to the cam follower, and the outside of the rotary shaft can be obtained. It is possible to reduce the width of the cam follower mounting portion by completely eliminating the above member, and it is possible to reduce the diameter of the cam follower provided on the rotating shaft, and to reduce the overall size.

According to the fourth means, by rotating the eccentric shaft by the rotating means, the cam follower can be moved toward and away from the cam by the eccentric amount. For example, when the eccentric shaft rotates 180 degrees, the eccentric amount is doubled. Can be moved, and the cam follower to be selected can be easily switched by bringing the selected cam follower into close contact with the cam. Therefore, it is not necessary to interpose a cylinder mechanism on the eccentric shaft, and only the bearing is required between the eccentric shaft and the cam follower, and the diameter of the cam follower can be reduced and the structure can be simplified.
Also, unlike the cam follower slide, the eccentric shaft can rotate and its power is small.

[Brief description of drawings]

1 to 6 show an embodiment according to the present invention, FIG. 1 is a sectional view of the first embodiment, FIG. 2 is a sectional view taken along the line I--I shown in FIG. 1, and FIG. A sectional view showing an embodiment, FIGS. 4 and 5 are sectional views showing a third embodiment, FIG. 6 is a schematic side view showing a driving portion of a transfer device, and FIGS. 7 and 8 are conventional examples. FIG. 1 ... Drive unit, 3 ... Cam shaft, 4A, 4B ... Cam, 5 ...
Support shaft, 6 …… Feed lever, 7 …… Cam follower, 11 ……
Fixed shaft, 13 …… Slide cylinder, 14 …… Bearing, 15 …… Cylinder hole, 15a …… Groove, 15b, 15c …… Oil chamber, 16A, 16B …… Fluid port, 18 …… Piston rod, 19 …… Connecting material, 41 …… Lever frame, 43 …… Bearing, 50 …… Shaft hole, 51 …… Rotary shaft, 51a …… Piston part, 51b …… Shaft part, 52 …… Cylinder part, 52c …… Cylinder hole, 53A, 53B ... Oil chamber, 54A, 54B ...
… Hydraulic supply hole, 63 …… Eccentric shaft, 63a …… Concentric part, 63b ……
Eccentric part, 64A, 64B …… Bearing, 65 …… Pinion, 66 …… Rack shaft, 68 …… Cylinder for switching.

Claims (3)

[Scope of utility model registration request] 1. A cam shaft (3) having a plurality of cams (4A, 4B) and a shaft (5) parallel to the cam shaft (3), which is swingably supported around the cam shaft (3). In a cam switching device including a lever (6) having a cam follower (7) that abuts against a lever, a fixed shaft (11) parallel to the cam shaft (3) is provided on the lever (6), and the fixed shaft (11) is attached to the fixed shaft (11). A slide cylinder (13) that is slidably fitted in the axial direction and that rotatably supports the cam follower (7) via a bearing (14) is provided on the outer peripheral portion of the fixed shaft (11). Cylinder hole (15) in which piston rod (18) is movably fitted
Is formed in the axial direction and the cylinder hole (15)
Is provided with two oil chambers (15b, 15c) for reciprocating the piston rod (18), and the cylinder hole (15) is provided with a groove (15a) opening to the outer peripheral surface at a position different from the oil chamber. 18) is formed along the moving direction of the piston rod (18) and the slide cylinder (1) through this groove (15a).
Cam switching device characterized by connecting 3). 2. A cam shaft (3) having a plurality of cams (4A, 4B) and a cam (4A, 4B) which is swingably supported around a shaft (5) parallel to the cam shaft (3). In a cam switching device including a lever (6) having a cam follower (7) that comes into contact with the cam follower (7), a rotating shaft (51) parallel to the cam shaft (3) is rotatably provided on the lever (6) via a bearing, The cam follower (7) is attached to the rotary shaft (51) through the shaft hole (51c).
Is externally fitted so as to be slidable in the axial direction, and the rotary shaft (51)
A piston part (51a) is provided so as to extend over the entire circumference in one of the outer peripheral surface of the cam follower and the shaft hole (51c) of the cam follower (7), and the other part is slidable in the axial direction in the piston part (51a). A cylinder hole (52c) for external fitting is formed, and hydraulic pressure supply holes (54A, 54B) for supplying and discharging pressure oil to and from the oil chambers (53A, 53B) formed on both sides of the piston portion (51a) are provided as rotary shafts. A cam switching device characterized by being provided in (51). 3. A cam shaft (3) having a plurality of cams (4A, 4B) and the cam (4A, 4B) swingably supported around a shaft (5) parallel to the cam shaft (3). In a cam switching device including a lever (6) having a cam follower (7) that abuts against the eccentric shaft (63), the lever (6) is rotatably provided with an eccentric shaft (63) parallel to the cam shaft (3). In (63), cam followers (7a, 7b) facing the cams (4A, 4B) are rotatably provided via the bearings (64a, 64b) at positions with different eccentric amounts, and the eccentric shaft (63) is rotated. Rotation means (65 ~
68) A cam switching device characterized by being provided.