JP5107784B2 - Pallet changer - Google Patents

Description

  The present invention relates to a pallet exchanging apparatus for exchanging a pallet on which a workpiece or the like is placed between a machine tool and a pallet conveying apparatus, for example.

For example, as a pallet exchanging device for exchanging a pallet on which a workpiece or the like is placed between a machine tool and a pallet conveying device, an exchanging arm having a pair of forks protruding in the opposite direction is provided so as to be able to move up and down and turn. Conventionally, this is generally known. In the pallet exchanging apparatus, the exchanging arm is moved up and down (or turned) by hydraulic pressure. However, such a structure using hydraulic pressure is not desirable from the viewpoint of energy saving.
Therefore, a pallet exchanging device that raises and lowers the exchanging arm using a cam and a lever instead of hydraulic pressure has been devised (for example, Patent Document 1).

Japanese Patent Publication No.7-110464

  In recent years, there have been cases where a mechanism for discharging chips is provided below the pallet changer. However, in the pallet exchanging device of Patent Document 1, a lever that is long in the vertical direction is used, and the height in the vertical direction of the pallet exchanging device becomes high. Therefore, a space for installing the mechanism below the pallet exchanging device. There was a problem that it was difficult to ensure. In addition, when a large pallet is exchanged or the mass of the workpiece placed on the pallet is large, a very large load is applied to the lever and the cam follower, and there is a problem that anxiety is caused in terms of durability.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a pallet exchanging apparatus that can be made compact in height in the vertical direction and excellent in durability.

In order to achieve the above-mentioned object, the invention according to claim 1 of the present invention includes an exchange arm having a pallet support portion capable of supporting a pallet, and moves the exchange arm up and down in the vertical direction. A pallet exchanging device for exchanging a pallet by turning it as a shaft, connected to the drive motor and rotating coaxially with the exchange arm below the exchange arm, and a cam on the upper surface in an arc shape A rotating plate disposed on the rotating plate, a cam follower mounted at an eccentric position on the upper surface or the lower surface of the rotating plate, and an engaging portion with which the cam follower can be engaged, and an axis parallel to the pivot axis of the exchange arm An engagement member installed so as to be swingable around, and swinging only when the cam follower is engaged with the engagement portion as the rotating plate rotates, and the replacement arm A gear portion fixed to the lower surface of the motor, and a transmission mechanism that connects the engagement member and the gear portion to rotate the replacement arm in conjunction with the swinging of the engagement member. When the rotating plate is rotated by operation, the exchange arm is pushed up by the cam, and then the cam follower is engaged with the engagement member, the engagement member is swung, and the cam follower is engaged with the engagement member. The replacement arm is lowered by the cam after the replacement arm is rotated by a predetermined angle in conjunction with the swing of the engaging member until it is released from the position.
According to a second aspect of the present invention, in the first aspect of the present invention, the mechanism for connecting the drive motor and the drive motor and the rotating plate to one side centered on the axis of the replacement arm is the other side. Further, the engaging member and the transmission mechanism are provided respectively.

According to the present invention, since the exchange arm is moved up and down by the cam provided on the upper surface of the rotating plate, the height in the vertical direction can be reduced as compared with a conventional device using a lever or the like. Therefore, it is possible to reduce the size of the pallet exchanging device, and it is possible to secure a sufficient space for installing a mechanism for discharging chips under the pallet exchanging device. In addition, since a member having a length in the vertical direction, such as a lever, is not used, the elevating mechanism and the turning mechanism are rich in durability, and can be used when replacing a large pallet with a large size. Can do.
According to the second aspect of the present invention, the drive motor and the mechanism for connecting the drive motor and the rotating plate are provided on one side around the axis of the replacement arm, and the engaging member and the transmission mechanism are provided on the other side, respectively. Therefore, the height in the vertical direction can be further reduced. Therefore, further downsizing of the pallet changer can be achieved.

  Hereinafter, a pallet exchanging apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory view showing a vertical cross section of the pallet exchanging apparatus, in which the right side of the center line L shows the raised state and the left side shows the lowered state.
The pallet exchanging device is for exchanging pallets P, P between a machine tool (not shown) and a pallet conveying device. The exchanging arm 2 can be moved up and down and turned on the upper surface of the frame 1 as described later. Be prepared for. A shaft hole 21 through which a shaft portion 31 protruding from the upper surface of the frame 1 can be inserted is provided at the center of the replacement arm 2, and the replacement arm 2 is fitted so as to be covered from above the shaft portion 31. It is disguised. Therefore, the exchange arm 2 turns around the shaft portion 31 and moves up and down along the shaft portion 31.

In addition, the exchange arm 2 is provided with a pair of forks 20, 20 protruding in the opposite direction, and the pallet P can be placed on the fork 20. Further, a pin hole 22 into which a positioning pin 6 protruding from the upper surface of the frame 1 can be fitted is formed in the base portion of each fork 20, and the replacement arm is inserted by inserting the positioning pin 6 into the pin hole 22. 2 is positioned at a predetermined exchange position, and inadvertent turning from the exchange position is prevented.
In addition, a cylindrical swivel gear 3 having a gear 3 </ b> A on the outer peripheral surface is fixed to the bottom surface of the exchange arm 2 coaxially with the swivel center of the exchange arm 2. The vertical length of the swivel gear 3 is such that the gear (gear part) 3A of the swivel gear 3 and the gear 15B of the third gear 15 opposite to the swivel gear 3 are engaged even when the exchange arm 2 moves up and down. The length is long enough to prevent it from coming off.

  Further, a donut-shaped disc 5 fitted to the shaft portion 31 is accommodated inside the swivel gear 3 so as to be slidable in the vertical direction. The disc 5 is in contact with the lower surface of the flange portion 3B protruding from the inner peripheral side of the swivel gear 3 via a thrust bearing. When the disc 5 is lifted by a drive mechanism described later, the swivel gear 3 That is, when the exchange arm 2 is also raised and the disk 5 is lowered, the exchange arm 2 is also lowered. Two first cam followers 4 and 4 are installed on the lower surface of the disk 5. In addition, the protrusion amount from the disk 5 lower surface of the 1st cam follower 4 and 4 installation parts is set larger than the protrusion amount of the cams 7A and 7A mentioned later.

  On the other hand, a first gear (rotary plate) 7 is attached below the disc 5 so as to be rotatable about the shaft portion 31. The first gear 7 is connected to the drive motor 12 through a second gear 9 installed on the left side thereof and facing the gear of the first gear 7 and pulleys 10 and 11. A pair of cams 7A and 7A for raising and lowering the disk 5, that is, the exchange arm 6, is provided on the upper surface of the first gear 7 via the first cam follower 4. As shown in FIGS. 3 and 4, each cam 7 </ b> A has an arc shape in plan view and is disposed on the concentric circumference of the first gear 7. The vertical height of the cam 7 </ b> A is determined by the positioning pin 6. It is high enough to get out of 22. Further, both end portions of each cam 7A are inclined surfaces 7B, and the first cam follower 4 contacting the upper surface of the cam 7A can be lifted smoothly as the first gear 7 rotates. Note that the first gear 7 is restricted from sliding in the vertical direction. Reference numeral 13 denotes a belt hung between the two pulleys 10 and 11.

  Further, a second cam follower 8 is provided at an eccentric position on the lower surface of the first gear 7 so as to protrude downward. As shown in FIG. 2, the right side of the first gear 7 has a fork portion (engagement portion) 14B that can engage the second cam follower 8 at one end, and a gear (transmission mechanism) at the other end. A Geneva (engagement member) 14 having 14 </ b> A is installed so as to be swingable around an axis parallel to the rotation axis of the first gear 7. Further, on the side of the Geneva 14, a gear having a gear 15A facing the gear 14A of the Geneva 14 and a gear having a gear 15B facing the gear 3A of the turning gear 3 are coaxially connected in the vertical direction. Three gears (transmission mechanism) 15 are installed to be rotatable around an axis parallel to the rotation axis of the first gear 7. As will be described later, the second cam follower 8 is provided at a position where the first cam follower 4 engages with the fork portion 14 after the first cam follower 4 is lifted by the cam 7A.

Here, the raising / lowering and turning operation | movement of the exchange arm 2 in the said pallet exchange apparatus is demonstrated.
First, the exchange arm 2 is initially in the lowered position where the positioning pin 6 is inserted into the pin hole 22, that is, the first cam followers 4 and 4 are between the cams 7A and 7A, and the pallet P is placed on each fork 20 in this state. Placed. When the drive motor 12 is operated from this state, the rotational torque is transmitted to the second gear 9 via the pulley 11, the belt 13, and the pulley 10, and the second gear 9 rotates and is opposed to the second gear 9. The first gear 7 rotates.

As the first gear 7 rotates, each first cam follower 4 is lifted onto the cam 7A via the inclined surface 7B, so that the exchange arm 2 is also raised via the disk 5, and the positioning pin 6 is moved to the pin hole. It will move to the ascending position that exits 22. At this stage, the second cam follower 8 is not engaged with the fork portion 14. Therefore, although the first gear 7 is rotating, the exchange arm 2 is prevented from turning.
After the first cam follower 4 is lifted by the cam 7A in this way, the second cam follower 8 is engaged with the fork portion 14B, the rotational torque is transmitted to the Geneva 14, and the Geneva 14 swings. Then, the third gear 15 rotates via the gear 15A facing the Geneva 14, and finally the rotational torque is transmitted to the turning gear 3 facing the gear 15B, so that the exchange arm 2 starts to turn.

  When the exchange arm 2 turns 180 degrees (that is, when the left and right pallets P and P are interchanged), the engagement between the second cam follower 8 and the fork portion 14B is released, and the Geneva 14, the third gear 15, As a result, turning of the exchange arm 2 stops. On the other hand, the first gear 7 continues to rotate, and the drive motor 12 is stopped when each first cam follower 4 is lowered between the cams 7A and 7A via the inclined surface 7B from the upper surface of the cam 7A. At this time, the exchange arm 2 is also lowered in synchronization with the first cam follower 4 and is positioned at the lowered position where the positioning pin 6 is fitted into the pin hole 22. Note that when the pallet P is exchanged by turning the exchange arm 2 again, the drive motor 12 is reversely rotated.

According to the pallet exchanging apparatus as described above, since the exchanging arm 2 is moved up and down by the cam 7A provided on the upper surface of the first gear 7, it is higher in the vertical direction than the conventional apparatus using a lever or the like. The thickness can be lowered. In addition, a structure in which the height is further lowered by including a drive unit including the drive motor 12 on one side and a turning mechanism of the exchange arm 2 including the Geneva 14 on the other side across the shaft unit 31 serving as a rotation shaft. It is said. Therefore, it is possible to reduce the size of the pallet exchanging device, and it is possible to secure a sufficient space for installing a mechanism for discharging chips under the pallet exchanging device.
In addition, since a member having a length in the vertical direction such as a lever is not used, the mechanism for raising and lowering and turning the exchange arm 2 is rich in durability, such as when exchanging a large pallet with a large size. Can also respond. Furthermore, since the exchange arm 2 is swung by the swing of the Geneva 14, the movement of the exchange arm 2 at the beginning and just before the turn can be made smooth.

  In addition, the structure which concerns on the pallet exchange apparatus of this invention is not limited to the aspect as described in the said embodiment at all, The structure of an exchange arm, various gears, an engaging member, a transmission mechanism, etc. is shown in this invention. As long as it does not deviate from the meaning, it can change suitably as needed.

  For example, in the above-described embodiment, a 360-degree gear is provided in the turning gear, the third gear, etc., but the gear may be provided only in a range necessary for turning the replacement arm (for example, in the above-described embodiment). In the case of the swirl gear of the form, it may be provided over about 200 degrees). Furthermore, when there is a distance between the third gear and the swivel gear, there is no problem even if another gear such as a fourth gear is interposed, and the swivel mechanism is located on either side of the shaft. The design can be changed as appropriate.

  In the above embodiment, the first gear and the drive motor are connected via the second gear or the like, but the first gear is directly connected to the drive motor or another connection mechanism using a belt or the like. The first gear may be a simple disc when these configurations are employed. Further, the engaging member is not limited to the Geneva of the above embodiment, and the shape and the like can be appropriately changed as long as the engaging member has the engaging portion. In addition, the transmission mechanism that transmits the swing of the engagement member to the gear portion of the exchange arm is not the transmission mechanism of the above-described embodiment including the gear provided on the Geneva and the third gear, but another belt or the like. It goes without saying that a transmission mechanism can be adopted.

Further, in the above-described embodiment, the cam is provided on the upper surface of the first gear and the second cam follower is provided on the lower surface. However, the first gear is formed to have a large diameter, and the second gear is further positioned at the outer peripheral position of the cam on the upper surface of the first gear. A configuration in which a cam follower is provided is also possible.
In addition, the raising and lowering and turning mechanism of the above embodiment can be applied to a pallet changing device in which a pallet is changed by turning an exchange arm having a pair of forks 90 degrees at right angles. The circumferential length, the protruding position, the installation position and the number of cam followers related to turning may be changed according to the turning operation.

It is explanatory drawing which showed the vertical cross section of the pallet exchange apparatus. It is explanatory drawing which showed a mode that a 1st gearwheel and the Geneva 14 engaged / disengaged. It is explanatory drawing which showed the turning gearwheel, the 1st gearwheel, and the 3rd gearwheel from upper direction. It is explanatory drawing which showed the 1st gearwheel and the disc 5 from the side.

Explanation of symbols

  1. Frame, 2 ... Exchange arm, 3 ... Swivel gear, 3A, 14A, 15A, 15B ... Gear, 4 ... First cam follower, 5 ... Disk, 6 ... Positioning pin, 7 ... 1st gear, 8 ... second cam follower, 9 ... second gear, 10, 11 ... pulley, 12 ... drive motor, 13 ... belt, 14 ... Geneva, 14B ... fork, 15 ... Third gear, 22 .. pin hole, 31 .. shaft part.

Claims (2)

A pallet exchanging device comprising an exchanging arm having a pallet supporting part capable of supporting a pallet, exchanging the exchanging arm in the vertical direction, and exchanging the pallet by turning about the vertical direction as an axis,
A drive motor;
A rotating plate connected to the drive motor, rotating coaxially with the replacement arm below the replacement arm, and having a cam disposed in an arc shape on the upper surface;
A cam follower attached at an eccentric position on the upper or lower surface of the rotating plate;
The cam follower has an engaging portion with which the cam follower can be engaged, and is installed so as to be swingable around an axis parallel to the pivot axis of the exchange arm. The cam follower engages with the engaging portion as the rotating plate rotates. An engaging member that swings only when
A gear portion fixed to the lower surface of the exchange arm;
A transmission mechanism that connects the engagement member and the gear portion and rotates the exchange arm in conjunction with the swinging of the engagement member;
When the rotating plate is rotated by the operation of the drive motor, the exchange arm is pushed up by the cam, the cam follower is then engaged with the engagement member, the engagement member is swung, and the cam follower is The pallet exchanging apparatus, wherein the exchanging arm is lowered by the cam after the exchanging arm is turned by a predetermined angle in conjunction with swinging of the engaging member until it is disengaged from the engaging member. The drive motor and a mechanism for connecting the drive motor and the rotating plate are provided on one side of the exchange arm as a center, and the engagement member and the transmission mechanism are provided on the other side, respectively. The pallet exchanging apparatus according to claim 1.

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