JPH08165027A - Tray changer - Google Patents

Abstract

PURPOSE: To quickly perform discharging a tray from an operating part while forming the dimension compact in a stroke direction of a mechanism for supplying the tray to the operating part. CONSTITUTION: In a tray changer device of vertical circulating method, supplying a tray 15 to an operating part C is performed by two-stage action of a large/small cylinder 23, 25, and in discharging the tray 15 from the operating part C, in addition to a lift mechanism of a step loading lift 43 by a linear motor, by additionally providing a lift mechanism of a receiving plate 48 by a step loading cylinder 46, discharging the tray 15 from the operating part C can be performed at a high speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tray changer, and more particularly to a tray changer suitable for automatic assembly by arranging the parts on the tray or taking out the parts on the tray in an operating part. .

[0002]

2. Description of the Related Art When a robot is used for automatic assembly, it is necessary to supply parts to be assembled by the robot to predetermined positions. Therefore, conventionally, a tray has been used. Recesses are formed on the tray at predetermined positions, and when parts are placed in these recesses and supplied to the operating part, the chuck of the robot hand takes out the parts on the tray and performs automatic assembly. Become.

[0003]

A tray changer for sequentially replacing trays for supplying the components used in such automatic assembly requires a mechanism for feeding the trays and feeding them to a predetermined operating portion. . As such a mechanism, a structure using a cylinder has been conventionally used.

However, if the rod cylinder is used, a space twice as much as a required stroke is required, so that the tray changer becomes unnecessarily large and wastes space. A rodless cylinder allows the tray to be delivered in a cylinder that is approximately the same length as the stroke, but the cylinder must be overhung at the front end of the stroke, requiring a large clearance at the rear end of the stroke. is there. As a result, the stroke becomes long, and it takes time to feed the tray.

Further, a mechanism using a motor or a combination of a rack and a pinion is used as a mechanism for arranging the parts on the tray in the operating part or for taking out the parts on the tray and then stacking and ejecting the trays. There is a structure to use. However, such a structure has a problem that tray stacking cannot be processed at high speed.

The present invention has been made in view of the above-mentioned problems, and the stroke of a cylinder for delivering a tray is shortened, or the components are arranged or removed. An object of the present invention is to provide a tray changer capable of processing an operation of stacking empty trays at high speed.

[0007]

SUMMARY OF THE INVENTION According to the present invention, trays to be supplied to an operating section in a tray separating section are stacked in a plurality of stages,
Moreover, the tray located on the bottom side is sequentially separated from the trays stacked on the upper side thereof, and the tray on the bottom side separated by the tray separating section is horizontally moved by the tray sending section and is sent out. The tray delivered from the delivery unit is positioned in the working unit. Then, arrange the parts on the tray in the operating part or take out the parts on the tray, and place the tray on which the parts are arranged or the tray on which the parts are taken out in the tray stacking part arranged under the operating part. Stack and stack until the specified number of sheets is reached,
When a predetermined number of trays are stacked and stacked in the tray stacking unit, the discharge unit discharges the trays.

Another aspect of the present invention is to hold a second cylinder in a mover for taking out a stroke of the first cylinder, and
The tray is moved by pressing the tray by pressing means connected to the mover of the second cylinder. Here, more preferably, both the first cylinder and the second cylinder may be rodless cylinders.

Still another aspect of the present invention is arranged between a position where a tray for receiving trays for receiving trays and stacking and stacking the trays is received by an elevating cylinder and a position where the stacked uppermost trays have a predetermined height. To move up and down,
Each time the receiving plate receives trays, the motor lowers the cylinder by a distance corresponding to the height of the stacked trays. Here, preferably, the motor is composed of a linear motor, and a stacking lift is attached to the mover, and the cylinder is held by the stacking lift via the mounting plate.

[0010]

According to the present invention, the tray located at the lowermost side in the tray separating section is separated from the tray stacked on the upper side, and the lowermost tray separated at the tray sending section is horizontal. Moved and sent out, parts are arranged in the above tray in the operating part, or parts on the tray are taken out, and the tray in which parts are arranged or the tray from which parts are taken out is the predetermined number in the tray stacking part The trays are stacked and stacked, and a predetermined number of sheets are stacked and stacked, and then the trays are discharged by the discharge unit.

According to another aspect of the invention, when the second cylinder is first actuated, the pressing means sends the tray a predetermined stroke, and then the first cylinder is actuated to move the mover of the tray. The cylinder is moved by this, and the tray is moved by the pressing means connected to the mover of the second cylinder to move to the second stage.

According to still another aspect of the invention, after the tray is raised by the cylinder to a position for receiving the tray and the tray is received, the cylinder is first lowered to a position where the uppermost tray has a predetermined height. Then, the motor further lowers by a distance corresponding to the height of the tray. After this, the receiving plate is again raised by the cylinder to a position for receiving the tray, and receives a new tray on the previous tray. Such an operation is repeated, and a predetermined number of trays are stacked and received on the receiving plate.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. This embodiment relates to a tray changer for automatic assembly. Particularly, as shown in FIG. 1, a tray 15 loaded by a flat tandem cylinder 18 is supplied to a tray delivery section B and two pen cylinders 17 ( The trays 1 are stacked by opening the holding plates 13 (see FIG. 3).
A tray separating section A for separating the lowermost tray 15 of the five is provided.

A tray delivery section B is provided below the tray separating section A. The tray 15 at the lowermost side separated in the tray separating section A is sent out by the combination of the strokes of the large cylinder 23 and the small cylinder 25, which are combined in the vertical direction, and the tray 15 is delivered especially at the upper side. By the cylinder 25, the tray 15 is sent out by the stroke of the initial stage, and after it is confirmed that there is no previous tray in the operating section C, the large cylinder 23 is advanced and the new tray 15 is sent to the operating section C.

The operating section C positions the tray 15 sent from the tray sending section B by a positioning plate 30 which is rotated by a dual cylinder consisting of a pair of cylinders 35 and 36 (see FIG. 5), and is newly supplied. Tray 15
The parts are arranged on the top or the parts in the tray 15 are taken out. Even when the tray 15 is discharged from the operating section C, the positioning plate 30 is opened by the dual cylinder including the cylinders 35 and 36.

A tray stacking section D is provided below the operating section C. When the tray 15 is full or the tray is emptied by taking out the tray in the operating section C, the stacking cylinder 46 and the linear motor 42 (see FIG. 6).
Thus, the trays 15 are stacked and stacked.

When a predetermined number of trays 15 are stacked and stacked in the tray stacking section D, the tray discharge section E
It is designed to be discharged to. The tray discharge section E is configured to discharge the trays 15 stacked in the tray stacking section D by the conveyor 51 when the trays 15 stacked up are full.

Next, the structure of each of the above A to E will be described.

As shown in FIG. 3, the tray separating portion A is provided with a pair of left and right guide rails 10, and an elevating frame 11 is supported by these guide rails 10 so as to be vertically movable. The holding plate 13 is rotatably supported by the lifting frame 11 via a support shaft 12 (see FIG. 1).

The holding plate 13 is provided with a claw 14 at its upper end, and is provided on the side of the lowermost tray 15 among the trays 15 stacked in a plurality of stages by such a claw 14 as shown in FIG. It is designed to support the projected ridges 16. These holding plates 13 are connected to pen cylinders 17 as shown in FIG. 3, and the opening and closing operations are performed by these pen cylinders 17.
Further, the elevating frame 11 is adapted to be moved up and down by a tandem cylinder 18 arranged between a pair of guide rails 10.

Next, the tray delivery section B will be described. The tray delivery section B is provided with holding plates 20 on the left and right as shown in FIGS. 3, 7, and 8, and these are fixedly arranged. The upper end of the holding plate 20 is bent outward to form a bent piece 21. Further, the holding plate 10 is cut out at predetermined two positions in the lengthwise direction to form a cutout 22. A large cylinder 23 composed of a rodless cylinder is arranged between the holding plates 20.
A small cylinder 25 is attached to the mover 24 of No. 3. The pressing plate 2 is attached to the mover 26 of the small cylinder 25.
7 is attached, and the pressing plate 27 presses the rear end of the separated tray 15 on the lowermost side.

Next, the structure of the operating portion C will be described.
As shown in FIGS. 5 and 6, the actuating portion C includes a pair of left and right positioning plates 30. The upper end of the positioning plate 30 is bent inward to form a holding piece 31, and the holding piece 31 supports the ridges 16 on both sides of the tray 15 from below. Further, a holding piece 32 is provided above the holding piece 31 of the positioning plate 30, and the holding piece 32 prevents the tray 15 from dropping upward.

The positioning plates 30 are rotatably supported by the support shafts 33, respectively. The one positioning plate 30 is connected to the rod of the cylinder 35, and the cylinder 35 is combined with another cylinder 36 in series. And these cylinders 35, 36
The left and right positioning plates 30 are connected to each other by a rod 37 in order to transmit the rotational movement of the one positioning plate 30 to the positioning plate 30 on the opposite side.

The pair of cylinders 35 and 36 (see FIG. 5)
As shown in FIG. 9, when the pair of cylinders 35 and 36 are both returned, the positioning plate 30 is closed and the tray is supported by the holding piece 31. 15 is correctly positioned in that position. On the other hand, a pair of cylinders 35, 36
When only one of the above, for example, the cylinder 35 is moved forward, the positioning plate 30 will be opened slightly (half open state) as shown in FIG. 10, and the tray on the holding piece 31 of the positioning plate 30 will be opened. 15 will be able to move.

When the pair of cylinders 35 and 36 are both moved forward, the positioning plate 30 is largely rotated and fully opened as shown in FIG. In this case, the holding piece 31
The tray support is lost by the
Will be received by. Fully open cylinder 3
Instead of summing the strokes of the two cylinders 5 and 36, the strokes of the pair of cylinders 35 and 36 are changed, and the half stroke cylinders show the half open state, and the large stroke cylinders show the full open state. You may do it.

Next, the construction of the tray stacking section D located below the operating section C will be described with reference to FIGS. 5 and 6. The tray stacking section D includes a pair of guide rods 40, and a linear guide 41 is provided at an intermediate position between the guide rods 40.
The linear motor 42 is supported so that it can be raised and lowered. The linear motor 42 is adapted to move the stacking lift 43 up and down.

The stacking lift 43 supports the mounting plate 45 via the columns 44. The stacking cylinder 46 is supported by the mounting plate 45. Further, the rod 47 of the stacking cylinder 46 is connected to the lower end of the receiving plate 48. The receiving plate 48 is a pair of guide rods 49.
It is guided by the stacking cylinder 46 to move up and down.

Next, the structure of the tray discharge section E will be described. As shown in FIGS. 1, 3, and 4, the tray discharge section E is composed of a conveyor 51, and the tray stacking section D has a receiving plate. When a predetermined number of trays 15 are stacked on the 48, the conveyor 51 performs a discharging operation.

Next, the control device for the tray changer will be described with reference to FIG. On the input side of the controller 55, a separating portion tray detection sensor 56 for detecting whether or not the tray 15 is present in the tray separating portion A, and a presence or absence of the tray 15 on the slide surface 21 of the tray feeding portion B are detected. Slide surface tray detection sensor 57,
The operating portion tray detection sensor 58 for detecting whether or not the tray 15 is properly positioned in a state of being sandwiched between the pair of positioning plates 30 of the operating portion C, and the small cylinder 25 at the maximum return position in the tray feeding portion B. A small cylinder backward movement detection sensor 59 for detecting whether or not the tray has moved up to the uppermost tray of the trays 15 stacked on the receiving plate 48 of the stacking section D, and whether or not the uppermost tray is at the uppermost position. Uppermost tray detection sensor 60, tray 4 of tray stacking section D
The lowest descent position receiving plate detection sensors 61 for detecting whether or not 8 is at the lowest descent position are respectively connected. Further, a tray discharge signal is input to the controller 55.

With such a controller 55, the tandem cylinder 18, the pen cylinder 17, the small cylinder 2
5, large cylinder 23, cylinders 35 and 36 forming a dual cylinder, linear motor 42, stacking cylinder 4
6 and the drive of the conveyor 51 are controlled respectively. In addition, the actuators 17, 18, 23, 25, 35, 36 constituted by air cylinders,
Regarding 46, the supply and discharge of air to and from these cylinders are controlled, and the controller 55 controls the intake valve and exhaust valve of these actuators.

Next, the overall operation of the tray changer having the above structure will be described with reference to the flow charts shown in FIGS.

First, the sensor 5 determines whether or not the trays 15 are stacked on the holding plate 13 of the tray separating section A.
It is performed based on the detection of 6 and waits if there is no tray. On the other hand, when there is at least one tray 15 in the tray separating section A, the tandem cylinder 18 causes the lowermost tray 15 to move by the bending piece 21 of the lower holding plate 20 shown in FIGS. 7 and 8. The frame 11 is lowered to the supported position. At this position, the sensor 57 detects whether the protrusion 16 of the tray 15 is caught on the slide surface, that is, the bent piece 21 of the holding plate 20. If the tray 15 is not detected here, the tray is stopped as an abnormality.

In the state where the trays 15 stacked to a predetermined position are lowered, the lifting frame 11 is supported by the support shaft 12.
The claws 14 of the holding plate 13 supported via the are located in the notches 22 of the holding plate 20 on the fixed side. When the holding plate 13 descends and its claw 14 enters the notch 22 of the holding plate 20 on the fixed side, the tray 15 is changed from being supported by the holding plate 13 to being supported by the holding plate 20. In such a state, the holding plate 13 is rotated around the support shaft 12 by the left and right pen cylinders (see FIG. 3), and the claw 14 of the holding plate 13 is disengaged from the lower portion of the protrusion 16 of the tray 15.

After this, the elevating frame 11 is raised by the first stroke by the tandem cylinder 18. Then, the claws 14 of the holding plate 13 are the tray 15 at the bottom side.
To the position corresponding to the lower surface of the ridge 16 of the tray 15 on the upper tier. Therefore, in such a state, the pen cylinder 1
By operating 7 in the opposite direction, the tray 15 at the second stage from the bottom is supported by the holding plate 13.

When the tray 15 in the second stage from the bottom is thus supported by the holding plate 13, the lifting frame 11 is further raised by the second stroke of the tandem cylinder 18 in this state. As a result, only the lowermost tray 15 is separated, and the holding plate 20 on the fixed side is separated.
The trays 15 placed on the movable frame 11 are separated from each other by holding the trays 15 stacked on the upper side thereof on the movable frame 11.

When the separation of the lowermost tray 15 is completed in this way, the sensor 57 detects whether or not the tray 15 is on the slide surface formed by the upper surface of the bent piece 21 of the holding plate 20. When the tray 15 is present, the upper small cylinder 25 is operated to move the mover 26 of the small cylinder 25 through the entire stroke.
This causes the bottom tray 15 to be advanced by about 1/4 of its length, as shown in FIG. Then, after this, the sensor 58 detects whether or not there is the tray 15 previously supplied to the operating portion C. Tray 15 is operating part C
If there is, wait here.

On the other hand, when the operating section C has no tray, the positioning plate 30 of the operating section C is half-opened. This operation is to operate only one of the pair of cylinders 35, 36 to change from the fully closed state shown in FIG. 9 to the half opened state shown in FIG. Positioning plate 30 only slightly
When the tray is opened, the tray 15 can move while sliding on the holding pieces 31 of these positioning plates 30.

In such a state, the sending section B
The large cylinder 23 of FIG. 7 (see FIG. 7) is operated to completely feed the new tray 15 into the operating portion C. When the large cylinder 23 is fully operated, the sensor 58 detects whether the tray 15 has been sent to the operating portion C, and
If it has not been completely delivered, take action to stop it abnormally. On the other hand, when the new tray 15 is completely fed, the positioning plate 30 is closed by the cylinder 35. As a result, the tray 15 newly supplied is positioned and held by the positioning plate 30. After this, the large cylinder 23 and the small cylinder 25 of the tray delivery section B are completely returned to prepare for the next tray 15 delivery.

Next, the tray stacking lift 43 of the tray stacking section D is raised to the upper end by the linear motor 42. Further, the stacking cylinder 46 raises the receiving plate 48 to the upper end. Then, when there is a tray ejection signal from the operating section C upon completion of the arrangement or removal of the parts in the operating section C, the positioning plate 30 is fully opened by operating the pair of cylinders 35 and 36. As a result, the support of the tray 15 by the holding piece 31 of the positioning plate 30 is lost. Therefore, the tray 15 is supported by the receiving plate 48 that stands by underneath.

When the tray 15 is received by the receiving plate 48, the stacking cylinder 46 is operated to lower the receiving plate 48 by the full stroke. Then, after that, the positioning plate 30 is fully closed by the operation of the cylinders 35 and 36, and the sensor 60 detects whether or not the tray 15 is present at a preset position which is the uppermost stack position. When there is the tray 15, the stacking lift 43 is lowered by the linear motor 42 by a distance corresponding to the height of one tray. Then, the linear motor 42 is stopped in a state where it is confirmed that the tray 15 is not provided at the uppermost position of the stack.

In this state, whether or not the tray 15 on the receiving plate 48 is full is detected by the sensors 60 and 61, and when the tray 15 is not full, the stacking cylinder 46 raises the receiving plate 48 to the upper end to move to the next tray. Prepare to discharge 15. Since the descending stroke of the stacking lift 43 is offset by the thickness of the trays 15 stacked on the receiving plate 48, the upper surface of the tray 15 at the uppermost stage of the receiving plate 48 is the tray 15 of the operating section C at this time. The receiving plate 48 is lifted to a height corresponding to the lower surface. Then, the positioning plate 30 is opened by the cylinders 35 and 36 to receive the next tray 15.

Then, the stacking cylinder 46 is used again until the uppermost tray 15 reaches the predetermined position.
The full stroke of the
The stacking lift 43 is lowered by a distance corresponding to one tray 15. Such a receiving plate 48
Repeat until trays 15 are stacked on top and full.
Then, when it is full, the sensor 61 confirms whether or not the receiving plate 48 is at the lower end (the lowest position), and the tray 51 is fed by the conveyor 51 of the tray discharge section E.
Discharge.

In the tray changer for exchanging the tray 15 in this manner, as shown in FIGS. 7 and 8, the tray 15 supplied to the slide surface constituted by the bent piece 21 of the holding plate 20 is first made small. The cylinder 25 pushes forward by about 1/4 of the total length of the tray 15 and temporarily stops and waits, and after the previous tray 15 is discharged in the operating section C, the large cylinder 23 moves it to the operating section C. The tray 15 is supplied. Since the tray separating portion A is located above the tray delivering portion B and the separated tray 15 is supplied from the upper portion to the slide surface 21, the escape of the rear end of the delivering cylinder 23 is prevented. It is necessary to take a lot. However, such a relief is secured by the small cylinder 25, and the tray 1
Since the escape portion is moved forward to stand by when feeding 5, the time required for sending out the tray 15 can be significantly shortened.

In the tray stacking section D provided below the operating section C, the stacking lift 43 is made to stand by at the upper end of the lift by the linear motor 42, and the stacking cylinder 46 raises the receiving plate 48. The tray 15 discharged from the operating section C is received by the receiving plate 48.

At this point, in order to quickly replace the tray 15 in the operating section C, first, the receiving plate 48 is lowered by the stacking cylinder 46, and at this stage, a new tray 15 is supplied by the sending section B. To do. Then, in order to stack and eject the trays 15 thereafter, the linear motor 42 lowers the stacking lift 43 by a stroke corresponding to the thickness of the trays 15 by detecting whether the trays 15 are in the stacking uppermost position. After escaping, the stacking cylinder 46 is raised again to prepare for the next stacking. Therefore, the stacking cylinder 46 moves the receiving plates 48 up and down between the uppermost stacking position and the receiving position of the tray 15. For this reason, the tray stacking section D reduces the waiting time for the tray sending section B as much as possible, and the tray 15 can be replaced at high speed.

[0046]

According to the present invention, the trays stacked in a plurality of stages are separated from the trays stacked on the upper side in the separating section, and the lowermost trays are separated. The tray sending unit horizontally moves the tray to the working unit and sends it, and the tray sent from the tray sending unit is positioned at the working unit, and further, the parts are arranged on the tray or the parts on the tray are taken out. A predetermined number of trays in which parts are arranged or trays from which parts have been taken out are sequentially stacked and stacked in a tray stacking part located below the operating part, and a predetermined number of trays are stacked and stacked. If so, the trays are discharged from the stacking section.

Therefore, according to this structure, a vertical circulation type tray changer having a compact overall size can be provided, and in particular, in its operating portion, the parts are arranged on the tray or the tray changer is arranged on the tray. Removing the parts will result in a tray changer that can be applied to automated assembly.

In another invention, the second cylinder is held by the mover for taking out the stroke of the first cylinder, the pressing means is connected to the mover of the second cylinder, and the tray is pressed by the pressing means. It was made to move. So 2 cylinders with each stroke
Since the tray changer is used by being overlapped with each other, the tray feed pitch and the escape pitch can be minimized, the supply stroke can be shortened, and the tray changer capable of moving the tray at high speed can be provided.

In particular, by constructing both the first cylinder and the second cylinder from rodless cylinders, it becomes possible to greatly reduce the dimensions of these cylinders in the stroke direction.

Still another invention is that a receiving plate for receiving and stacking trays is moved up and down by a cylinder between a position for receiving the trays and a position where the uppermost stacked trays have a predetermined height. Each time the receiving plate receives trays, the cylinder is lowered by the motor by a distance corresponding to the height of the stacked trays. Therefore, when the trays are stacked and discharged, the trays are first lowered by the cylinder, so that the required stroke can be processed at high speed, and the time required for tray replacement can be shortened. .

When the above-mentioned motor is composed of a linear motor and a stacking lift is attached to the mover and the cylinder is held by the stacking lift via the mounting plate, the receiving plate is moved up and down and the cylinder is gradually lowered. It is possible to simply configure a stacking mechanism that smoothly operates.

[Brief description of drawings]

FIG. 1 is a front view showing the overall configuration of a tray changer.

FIG. 2 is a plan view of a tray changer.

FIG. 3 is a right side view of the tray changer.

FIG. 4 is a left side view of the tray changer.

FIG. 5 is an enlarged side view of an essential part showing the configuration of an operating part.

FIG. 6 is an enlarged front view of a main part showing the configuration of a tray stacking unit.

FIG. 7 is an enlarged front view showing a tray separating unit.

FIG. 8 is an enlarged side view showing a tray separating unit.

FIG. 9 is a side view showing a tray holding operation by a positioning plate.

FIG. 10 is a side view showing the rotating operation of the positioning plate.

FIG. 11 is a side view showing the rotating operation of the positioning plate.

FIG. 12 is a block diagram of a control device of the tray changer.

FIG. 13 is a flowchart showing the operation of the tray changer.

FIG. 14 is a flowchart showing the operation of the tray changer.

[Explanation of symbols]

 A tray separating part B tray sending part C operating part D tray stacking part E tray ejecting part 10 guide rail 11 lifting frame 12 supporting shaft 13 holding plate 14 claw 15 tray 16 ridge 17 pen cylinder 18 tandem cylinder 20 holding plate 21 Bending piece 22 Notch 23 Large cylinder 24 Mover 25 Small cylinder 26 Mover 27 Pressing plate 30 Positioning plate 31 Holding piece 32 Holding piece 33 Spindle 35, 36 Cylinder 37 Rod 40 Guide rod 41 Linear guide 42 Linear motor 43 steps Stacking lift 44 Strut 45 Mounting plate 46 Stacking cylinder 47 Rod 48 Receiving plate 49 Guide rod 51 Conveyor 55 Controller 56 Separation part tray detection sensor 57 Sliding surface tray detection sensor 58 Actuation part tray detection sensor 59 Small cylinder return detection sensor 60 uppermost position the tray detection sensor 61 lowest position receiving plate detecting sensor

Claims (5)

[Claims] 1. A tray separating unit in which trays supplied to an operating unit are stacked in a plurality of stages, and a tray located at the bottom is sequentially separated from trays stacked above the tray, and the tray separating unit. Located on the lower side of the tray and horizontally moving the separated bottom tray to the operating section and sending out the tray, and positioning the tray sent out from the tray sending section, and placing it on the tray. An operating part for arranging the parts or taking out parts on the tray, and a tray located below the operating part for sequentially stacking a predetermined number of trays in which the parts are arranged or trays from which the parts are taken out. A tray changer comprising: a stacking unit; and a tray discharging unit that discharges the trays when a predetermined number of trays are stacked and stacked in the tray stacking unit. 2. A first cylinder adapted to take out a stroke by a mover, a second cylinder held by the mover of the first cylinder, and a mover of the second cylinder. A tray changer comprising: a pressing plate that is connected to the tray and presses the tray to move. 3. The tray changer according to claim 2, wherein both the first cylinder and the second cylinder are rodless cylinders. 4. A receiving plate for receiving trays and stacking and stacking the trays, and raising and lowering the receiving plates between a position where the trays are received and a position where the stacked uppermost tray has a predetermined height. And a motor for lowering the cylinder by a distance corresponding to the height of trays stacked each time the receiving plate receives the trays. 5. The motor comprises a linear motor,
The tray changer according to claim 4, wherein a stacking lift is attached to the mover, and the cylinder is held by the stacking lift via a mounting plate.