JPH09310743A - Conjugate cam device and planer-type operating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constrain the movement of a cam follower by forming a curved surface of two plate cams so as to be divided to a cam surface for constraining the forward pushing movement and the backward pushing movement and a cam surface for constraining the backward pushing movement and the forward pushing movement, and forming them so that both the pushing movements are smoothly continued. SOLUTION: One end of a forward movement lever 20 is supported by a support shaft 11a freely to be turned, and one end of a backward movement lever 21 and one end of a vertical movement lever 22 are supported by a rear support shaft 11b freely to be turned. A turning surface of each lever 20, 21 for forward movement and backward movement is set between plate cams 17, 18 for forward movement and backward movement. A turning surface of the vertical movement lever 22 is set between the plate cam 18 for backward movement and the plate cam 19 for vertical movement. A curved surface of the plate cam 17 for forward movement is formed so as to constrain a cam follower 43 of a side of the plate cam 18 for backward movement with the cam surface at the time of forward movement and backward movement of a linear moving body. A curved surface of the plate cam 18 for backward movement is formed so as to constrain a cam follower 41 of a side of the plate cam 17 for forward movement with the cam surface. Jumping of the cam follower is thereby eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cam device for converting a rotary motion into a linear motion and a gate type motion device utilizing this device.

[0002]

2. Description of the Related Art When a rotary motion is converted into a reciprocating linear motion by a plate cam having a cam curved outer surface and a cam follower, the cam follower is normally pushed by the cam at the time of forward movement and is restrained by the cam. When moving, it requires pressing by a spring. Therefore, when the plate cam operates at high speed,
The cam follower may be separated from the cam surface of the plate cam (jumping) due to the inertia of the cam follower or a member that moves together with the cam follower.

If there is jumping, the operation timing is deviated and the working accuracy of the originally supposedly accurate cam is deteriorated. In addition, a jumping shock may cause noise or damage the mechanism.

By using a so-called grooved cam in which a cam groove is provided along the peripheral surface of the rotating disk and the cam follower travels in this groove, the cam follower is restrained by the cam groove both during the forward and backward movements of the linear motion. Therefore, jumping does not occur. However, the groove cam must have a clearance between the cam follower and the cam groove in order for the cam follower to move smoothly, and therefore a small amount of play cannot be eliminated. In a device that uses a lever to transmit the displacement of the cam follower to the linear moving body, a small amount of backlash on one end side may become a nonnegligible size on the other end side of the lever due to the lever ratio.

Further, since the groove cam itself is large (the diameter is large and the thickness is large) and tends to be heavy, the groove cam is not suitable for high speed operation.

[0006]

SUMMARY OF THE INVENTION The present invention is provided with a cam mechanism for converting a rotary motion into a linear motion by using a plate cam having a cam curved surface on the outer periphery, and the linear motion is either forward or backward. Also, it is an object to provide a conjugate cam device in which the cam follower is acted by the plate cam, and to provide a portal type operation device whose operation is accurate and reliable.

[0007]

[Means for Solving the Problems]

[Conjugate cam device] A cam device provided with a linear moving body having two plate cams attached to the drive shaft, a cam follower, and two guide blocks, and converting the rotation of the drive shaft into a reciprocating linear motion of the linear moving body. To do. The axes of Cartesian coordinates are set to X, Y, and Z, and the machine wall in the Z direction is provided. Two plate cams are fixed to the same drive shaft mounted in the Y direction. The plate cam is a thick steel plate whose outer circumference is a cam curved surface along a cam curve, and the cam curve is determined by continuously determining points at a predetermined distance from the rotation center for each rotation angle. The two plate cams are
Usually the cam curves are different.

A forward guide block and a backward guide block are attached to the linear moving body, and the linear moving body is supported by a linear guide or the like against the machine wall so as to be reciprocally movable in the X direction. Each guide block can be guided in the Z direction by a groove or the like formed in the Z direction. The displacement of the cam follower due to the rotation of the plate cam is transmitted to the linear moving body via the guide block. Of the displacement of the cam follower, the displacement in the Z direction is absorbed by the guide block, and only the displacement in the X direction is transmitted to the linear moving body. A lever may be interposed between the cam follower and the guide block of the linear moving body.

The two plate cams are used for advancing and retreating with respect to the reciprocating movement of the linear moving body, and the advancing plate cam takes charge of the cam curved surface for forward pushing and restraining action at the time of backward movement (prevention of jumping). The cam for the retreat plate is distributed (conjugated) so that the cam curved surface performs the restraining action (jumping prevention) during backward pushing and forward movement, and both pushing actions and restraining action for jumping prevention are smooth. Both cam curved surfaces are formed so as to be continuous with. In reality, the necessary data is input to the computer running the cam creation software to create a cam curve (cam curved surface).

When the drive shaft is rotated, the plate follower is rotated to displace the cam follower, and the linear moving body is reciprocated in the X direction. At this time, the cam followers contacting the forward and backward plate cams are constrained by these cam curved surfaces both when the linear moving body is moving forward and when moving backward.
The movement of the linear moving body is always performed with the cam follower constrained by the cam curved surface, and there is no room for rattling or jumping, and the reciprocating movement is reliable and accurate.

The displacement of the cam follower may be transmitted to the linear moving body by using a lever. The lever is a forward lever and a backward lever, and they are arranged on both sides of the drive shaft. Each of the levers has one end in the Z direction rotatably supported on the machine wall by a support shaft in the Y direction, a cam follower arranged at an intermediate portion, and a driven portion provided at the other end. The forward guide block guides the driven portion of the forward lever, and the backward guide block guides the driven portion of the backward lever.

Although there are two levers and they are arranged at both sides of the drive shaft, two cam followers contacting the forward and backward plate cams are used when the linear moving body is moving forward or backward. Be bound by the cam curve of. The driven portion of the forward lever contacts only the forward side wall of the forward guide block, and the driven portion of the backward lever contacts only the backward side wall of the backward guide block. Therefore, there is no rattling in the guide block that moves from the advancing side wall to the retracting side wall when the movement direction is changed with respect to the movement of the linear moving body. Further, by using the lever, the linear moving body can be arranged at a position away from the contact point between the plate cam and the cam follower, and the displacement of the cam follower can be enlarged and transmitted to the linear moving body.

The cam followers of the forward lever and the reverse lever may be arranged so as to be eccentric to the facing surfaces of these levers. With this configuration, the cam follower and the plate cam are close to the center of rotation, and the plate cam can be made small and lightweight. As a result, the inertia of the plate cam is reduced,
The accuracy of linear movement can be improved.

[Gate-type operating device] X, Y,
As Z, a Z-direction feed cam mechanism, an X-direction feed cam mechanism, and a linear moving body that can move in the X direction are provided, and a top plate attached to the tip of the linear moving body is used by these cam mechanisms in the X and Z directions. It is a device that makes a gate-type movement that combines the movements of. Either or both of the Z-direction feed cam mechanism and the X-direction feed cam mechanism in this device are used as a conjugate cam device. The conjugate cam device ensures reliable and accurate operation, which improves the working accuracy of the portal motion device.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The figure shows a gate-type operating device 1 including a machine casing 2, a motor 3 and a speed reducer 4 (FIG. 3). The machine casing 2 includes left and right side plates (machine walls) 5 and 6 and a top plate 7.
The top plate 7 has a sturdy structure including the bottom plate 8 and the reduction gear 4 is further mounted on the top surface of the top plate 7 and the motor 3 is mounted on the top surface thereof. For convenience of description, the Cartesian coordinates are defined as shown in FIG. 1, and the X direction is the front and back, the Y direction is the left and right, and the Z direction is the up and down. The side plates 5 and 6 are machine walls and extend in the Z direction.

A transmission shaft 9, a drive shaft 10 (FIG. 3) and a support shaft 11 are provided between the left and right side plates 5 and 6 of the machine casing 2.
(FIGS. 4 and 1) are mounted in parallel in the Y direction. A passive bevel gear 12 and a small spur gear 13 are fixed to the transmission shaft 9, and the passive bevel gear 12 meshes with a drive bevel gear 15 attached to an output shaft 14 of the speed reducer 4. Drive shaft 10
Has a large spur gear 16 and three plate cams 17, 18, 19,
That is, the forward plate cam 17, the backward plate cam 18, and the vertical plate cam 19 are fixed, and the small spur gear 13 is meshed with the large spur gear 16. Therefore, motor 3
Is driven, the plate cams 17, 18, and 19 are driven and rotated via the speed reducer 4, the bevel gears 12 and 15, and the spur gears 13 and 16.

The support shaft 11 has a front support shaft 11a and a rear support shaft 11b (FIGS. 1 and 2), and one end (upper end) of a forward lever 20 is rotatably supported on the front support shaft 11a. Is
One end of a retreat lever 21 and one end of a vertical lever 22 are rotatably supported on the rear support shaft 11b. The rotation surfaces of the forward and reverse levers 20 and 21 are set between the forward and reverse plate cams 17 and 18, and the vertical surface of the up and down lever 22 is the reverse cam plate 18 and the vertical plate. It is set between the cams 19.

On the inner surface side of the right side plate 6 of the machine casing 2, a vertical linear guide 23 is fixed to the lower part on the front side (FIG. 1), and its angular axis slider 24 is movable in the vertical direction. . An end plate 25 is fixed to the upper part of the angular axis slider 24, and a linear guide 26 in the front-rear direction is attached to the lower part. In this embodiment, the lower portion of the rectangular axis slider 24 has a spline structure. The square axis slider 24 may be an axis having a non-circular cross section having a rotation preventing function. The linear guide 26 is connected to the angular axis slider 24 by a connector 27, and the connector 27 is fixed to the angular axis slider 24 so as to sandwich the angular axis slider 24 with a guide plate 28 (FIG. 4). The linear guide 26 is attached to the angular axis slider by sandwiching the connector 27 with the guide plate 28, but the connector 27 may be directly fixed to the angular axis slider 24. However, the sandwiching structure as described above can increase the rigidity of the portion where the linear guide 26 is fixed to the angular axis slider 24.

The slider 2 of the linear guide 26 in the front-rear direction
A linear moving body 30 is fixed to 9, and a forward guide block 31 and a backward guide block 32 are further provided on the outer surface side thereof.
It is attached to the rear portion of the linear moving body 30 at a distance. The linear moving body 30 is a single rod having high rigidity, and has a top plate attached to the front end thereof or a work tool (chuck or the like) directly attached thereto. Information blocks 31,3
2 includes guide grooves 33 and 34 in the Z direction, and the grooves are formed by front and rear walls 35 (a, b) and 36 (a, b), respectively.

A bracket 37 is formed so as to project in the middle of the guide plate 28, and a lower portion of a guide rod 38 having one end fixed to the top plate 7 is slidably fitted. A spring 40 is attached to the guide rod 38 between a fixing ring 39 and a bracket 37, and always urges the bracket 37, that is, the angular axis slider 24 downward.

The forward lever 20 (FIG. 5) has a cam follower 41 made of a roller at an intermediate portion and a driven portion 42 also made of a roller at the other end. Cam follower 4
1 is designed to always contact the outer periphery of the advancing plate cam 17, that is, the cam curved surface, and the driven portion 42 contacts the front wall 35a of the advancing guide block 31.

Similarly, the reversing lever 21 (FIG. 6) has a cam follower 43 made of a roller at the intermediate portion and a driven portion 44 made of a roller at the other end. Cam follower 43
Always contacts the cam curved surface of the retreat plate cam 18, and the driven portion 44 contacts the rear wall 36b of the retreat guide block 32. The displacement in the Z direction due to the displacement of the cam followers 41, 43 is absorbed by the guide grooves 33, 34, and only the displacement in the X direction is transmitted to the linear moving body 30.

In this embodiment, the cam follower 41 of the forward lever 20 and the cam follower 43 of the reverse lever 21 are displaced to the side of the surfaces where the levers 20 and 21 face each other as shown in FIGS. Are arranged. With this structure, the cam followers 41, 43 approach the drive shaft, and the size of the plate cams 17, 18 can be reduced. Guide block 31 for forward and backward
The width of the guide grooves 33, 35 of 32 is larger than the diameter of the driven portions 42, 44 and is formed with a margin.
The movement of 44 is not hindered.

The up / down lever 22 (FIG. 7) is arranged substantially in the X direction, and the cam follower 4 having a roller in the middle thereof.
5 has a driven portion 46 composed of a roller at the other end. The cam follower 45 is always in contact with the cam curved surface of the vertical plate cam 19, and the driven portion 46 is in contact with the lower surface of the end plate 25.

The cam curves of the plate cams 17, 18 and 19 are different from each other as shown in the figure, and the computer running the cam making software can determine the rotation direction of the plate cam, the support point of the lever, the lever length, Input various data such as the radius of the cam at the start, the center of rotation of the cam and the position (coordinates) of the driven part, the radius of the cam follower, etc.
A cam follower 43 on the side of the retreat plate cam 18 is constrained to the cam surface when the linear moving body is pushed forward and backward, and is formed so as to be responsible for preventing irregular movement of the linear moving body 30 caused by the jump of the cam follower. The cam curved surface of the reverse plate cam restrains the cam follower 41 on the forward plate cam 17 side to the cam surface at the time of backward movement and forward movement, and prevents the irregular movement of the linear moving body 30 due to the jump of the cam follower. It is formed so that the functions are distributed and conjugated, and both pushing and restraining actions are smoothly continuous.

The plate cams 17, 1 shown in FIGS. 5, 6 and 7.
The cam curves 8 and 19 are made as close as possible to the actual cam curves thus obtained. The cam follower positions with No correspond to the switching points (start point and end point) of the operation direction in the gate type operation. The cam creation software requires some modification depending on the actual situation, but commercially available basic software can be used.

The cam followers 41 and 43 contacting the cam curved surface of the advancing plate cam 17 and the cam curved surface of the retreating plate cam formed as described above are both cam curved surfaces both when the linear moving body 30 is advancing and when it is retracting. Therefore, in the end, the movement of the linear moving body 30 in the X direction is always performed with the two cam followers constrained by the cam curved surfaces. Therefore, there is no room for rattling or jumping during the rotation of the plate cam, and the reciprocating motion is reliable and accurate.

The gate-type operating device 1 having the above-described structure includes a Z-direction feed cam mechanism having an up / down lever 22, an X-direction feed cam mechanism having forward / backward levers 20 and 21, and an X-direction feed cam mechanism. A device for moving a top plate attached to the tip of the linear moving body 30 by a linear movement body 30 capable of moving in a direction, and performing a gate-type movement combining movements in the X direction and the Z direction by these cam mechanisms. It corresponds to a device in which the direction feed cam mechanism is a conjugate cam device.

When the plate cams 17, 18 and 19 are driven and rotated by the drive shaft 10 in the gate type operating device 1 (FIG. 2), the displacement of the cam followers 41, 43 and 45 causes
The levers 20, 21 and 22 rotate, and the driven parts 42 and 44 at the tip end are moved to the guide block 3 at a predetermined timing.
Pushing 1, 32 forward or backward,
The driven portion 46 moves up and down the end plate 25 (downward movement is by the spring 40).

As a result, the linear moving body 30 reciprocates back and forth (X direction) and moves up and down (Z direction), and the top plate attached to the tip of the linear moving body 30 can be moved in a gate shape. . The gate operation can be used for a so-called pick and place machine used in an assembly line or the like. And this gate-type operating device 1
Since the X-direction feed cam mechanism is a conjugate cam device, the X-direction feed does not rattle in the X-direction feed and operates reliably, so that the working accuracy is high.

Although the embodiment has been described above, X,
The correspondence between the Y and Z directions and the front-rear, left-right and up-down directions changes depending on the actual arrangement of the conjugate cam device or the gate type operating device.
In the gate-type operation device 1, in addition to the X-direction feed cam mechanism, the Z-direction feed cam mechanism can be a conjugate cam device.

[0032]

According to the structure described in claim 1, the two plate cams fixed to the same drive shaft are used for forward and backward restraining and backward pushing for the reciprocating movement of the linear moving body. Also, since the movement of the cam follower is restricted in both forward and backward movements for restraint during forward movement, it is not necessary to rely on the spring bias for movement during backward movement, and the jumping of the cam follower is eliminated. This enables high speed rotation of the plate cam.

According to the second aspect of the invention, by using the two levers for advancing and retracting, the linear moving body can be arranged at a position apart from the contact portion between the plate cam and the cam follower. The structure of the conjugate cam device can be simplified and the displacement of the cam follower by the plate cam can be enlarged.

According to the structure of claim 3, the distance between the cam follower and the cam drive shaft is small, the size of the two plate cams in the conjugate cam device can be reduced, and a lightweight and compact conjugate cam device is manufactured. it can. According to the configuration described in claim 4, it is possible to obtain the gate-type operating device which is surely operated and has high working accuracy.

[Brief description of drawings]

FIG. 1 is a perspective view showing a part of the structure in a cutaway manner.

FIG. 2 is a side view schematically showing the mechanism.

FIG. 3 is a front view showing a part in section (partially omitted).

FIG. 4 is a rear view showing a part in section (partially omitted).

FIG. 5 is a side view showing a plate cam for advancing.

FIG. 6 is a side view showing a plate cam for retracting.

FIG. 7 is a side view showing plate cams for vertical movement.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gate type operating device 2 Machine casing 3 Motor 4 Speed reducer 5 Left side plate 6 Right side plate 7 Top plate 8 Bottom plate 9 Transmission shaft 10 Drive shaft 11 (a, b) Support shaft 12 Passive bevel gear 13 Small spur gear 14 Output shaft 15 Drive Bevel Gear 16 Large Spur Gear 17 Forward Plate Cam 18 Backward Plate Cam 19 Up / Down Plate Cam 20 Forward Lever 21 Backward Lever 22 Up / Down Lever 23 Vertical Linear Guide 24 Square Shaft Slider 25 End Plate 26 Front-Back Direction Linear guide 27 Connector 28 Guide plate 29 Slider 30 Linear moving body 31 Forward guide block 32 Backward guide block 33 Guide groove (for forward movement) 34 Guide groove (for backward movement) 35 (a, b) Front and rear walls 36 (a , B) Front and rear walls 37 Bracket 38 Guide rod 39 Fixing ring 40 Spree Ng 41 cam follower (for forward movement) 42 driven portion 43 cam follower (for backward movement) 44 driven portion 45 cam follower (for vertical movement) 46 driven portion

Claims (4)

[Claims] 1. A pair of plate cams fixed to the same drive shaft and having cam curved outer surfaces, cam followers in contact with the respective cam curved surfaces, two guide blocks for absorbing deviation, and a linear moving body, With the axes of Cartesian coordinates as X, Y, and Z, the drive shaft is mounted in the Y direction on the machine wall extending in the Z direction, and the linear moving body can be moved back and forth in the X direction. One guide block is moved forward in the linear moving body. For use now, one for backwards,
The guides are fixed in the Z direction, and the displacement of the cam followers in the X direction is transmitted to the linear moving body via the guide block. The cam curved surfaces of the two plate cams are pushed forward and backward and restrained and retracted. A conjugate cam device characterized in that it is distributed for restraint during movement and forward movement, and is formed so that both pushing movements smoothly continue. 2. A forward lever and a backward lever are provided at both sides of the drive shaft, and one end side in the Z direction is Y.
Rotatably supported by the support shaft in the direction of the machine wall, the cam follower is arranged in the middle part of the lever, the driven part on the other end side of the lever is provided, and the driven part of the forward lever is guided to the forward guide block. 2. The conjugate cam device according to claim 1, wherein the backward guide block guides the driven portion of the backward lever. 3. The conjugate cam device according to claim 2, wherein the cam followers of the forward movement lever and the backward movement lever are arranged so as to be deviated to the facing surface side of these levers. 4. A cam mechanism for feeding in the Z direction, a cam mechanism for feeding in the X direction, and a linear moving body movable in the X direction with the axes of Cartesian coordinates as X, Y, Z, and attached to the tip of the linear moving body. The top plate can be
A device for performing a gate-type movement that combines movements in the Z direction and the Z direction, wherein either one of a Z-direction feed cam mechanism and an X-direction feed cam mechanism is defined in any one of claims 1 to 3. The conjugate cam device according to claim 1, or both the Z-direction feed cam mechanism and the X-direction feed cam mechanism, the conjugate cam device according to any one or two of claims 1 to 3,
Gate-type operating device characterized by being.