Workpiece feeding and returning device in a board cutting machine, and a board cutting machine to which the same is applied.

Abstract

Regarding a board cutting device that cuts intermediate workpieces from a long workpiece, the technical challenge was to develop a workpiece feeding and retraction device that can push the long workpiece to the cutting position while slightly retracting the remaining long workpiece, and a board cutting device that applies this device. [Solution] The workpiece feeding and returning device 2 of the present invention comprises a traveling beam, a lifting frame supported by the traveling beam and shifted up and down by a lifting shift cylinder 36, and an extrusion chuck unit 5 supported by the lifting frame. The extrusion chuck unit 5 comprises an extrusion plate 51 that is supported by a unit support arm 44 of the lifting frame and can protrude forward, a chuck plate 55 that is movable in the vertical direction, and a lower pressing claw 54 provided below the chuck plate 55. The lifting frame is characterized in that a biasing means S is provided between the lifting frame and the traveling beam to slightly raise the lifting frame when the pressure of the lifting shift cylinder 36 is released.

Description

Technical Field

[0001] The present invention relates to a board cutting device, and particularly to a work feeding and returning device in a board cutting device that can push a long workpiece to a cutting position to obtain an intermediate workpiece from the long workpiece and slightly retract the remaining long workpiece, and a board cutting device to which this is applied.

Background Art

[0002] For example, wood-based board materials that make up furniture, kitchen countertops, etc. are cut out from raw materials according to product specifications. First, the raw material is cut into a long shape to form a long workpiece with a certain width, and then this long workpiece is cut into a short shape in the longitudinal direction, for example, to obtain an intermediate workpiece. In this process, the intermediate workpiece cut from the long workpiece is dropped into the gap between the remaining long workpiece after splitting with a scraping body for transfer, and a work scraping device that supports the scraping body moves forward in front of the device to move the intermediate workpiece forward.

[0003] To ensure such transfer, the scraping body needs to be surely dropped into the gap after cutting, and an operation is performed to slightly widen the gap. This operation is substantially performed by pulling back to slightly retract the remaining long workpiece, and the pushing device that is responsible for pushing the long workpiece holds the rear end of the workpiece and pulls it back. At this time, if the remaining long workpiece on the transfer table is pulled back in its original posture, since the entire range of the lower surface of the long workpiece is in contact with the conveying surface (transfer table), the pulling-back resistance (frictional resistance) is large, and there is a risk that the holding of the long workpiece may be released. Therefore, in the process of pulling back the long workpiece, the rear end of the workpiece held by the pushing device is slightly lifted so that only the front end of the workpiece is in contact with the conveying surface, and it is pulled back in a state where the frictional resistance during movement is reduced. Incidentally, in order to realize such a process, the lifting and lowering shift cylinder is used to perform actions such as slightly raising the holding member that holds the long workpiece. However, in order to obtain a slight lifting system, measures such as using a special specification 3-position type lifting and lowering shift cylinder or providing a separate dedicated cylinder for slight lifting were necessary. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-206201 [Patent Document 2] Japanese Patent Application Publication No. 9-1501 [Overview of the project] [Problems that the invention aims to solve]

[0005] This invention was made in consideration of the above background, and the technical challenge was to develop a workpiece feeding and returning device that can slightly raise the holding member without making any special changes to the specifications of the shift cylinder itself, and a board cutting device to which this device is applied. [Means for solving the problem]

[0006] In other words, the workpiece feeding and returning device in the board cutting device according to claim 1 is A workpiece feeding and retraction device that, when cutting a long workpiece into shorter lengths, pushes the rear end of the long workpiece to feed the leading end of the long workpiece to the cutting position, and at the same time holds and pulls back the remaining rear end of the long workpiece after cutting, causing it to retract slightly backward, This workpiece feeding and return device is A traveling beam supported by a frame and moving in the workpiece feeding direction, This lifting platform is supported by a travel beam and is raised and lowered by a lifting shift cylinder, This system comprises an extrusion chuck unit supported on a lifting platform, This extrusion chuck unit is An extruded plate supported by a unit support arm on a lifting platform, which can freely protrude forward, A chuck plate that can move freely in the vertical direction, This chuck plate is equipped with a lower retaining claw located below it. The aforementioned lifting platform is characterized in that a biasing means is provided between the lifting platform and the travel beam, which slightly raises the lifting platform when the pressure of the lifting shift cylinder is released.

[0007] Furthermore, the workpiece feeding and returning device in the board cutting device according to claim 2, in addition to the requirements of claim 1, The biasing means is a compression coil spring, and this compression coil spring is characterized in that its lower end surface is supported on the travel beam side and biases the lifting platform upward.

[0008] Furthermore, the workpiece feeding and returning device in the board cutting device according to claim 3, in addition to the requirements of claim 1 or 2, The chuck plate is attached to the front side of an extension arm that is configured to move up and down relative to the unit support arm. Furthermore, the lifting platform comprises a plurality of support legs provided in the front-rear direction, and guide sleeves provided on the outer circumference thereof to be slidable. Of these, the support legs are provided to connect the chuck cylinder support plate and the bottom plate member of the unit support arm. When lowering the chuck plate and holding the rear end of the long workpiece between the chuck plate and the lower clamping jaws, This system is characterized by the fact that, as the extension arm descends, the guide sleeve slides downward along the outer circumference of the support leg, allowing the extension arm to descend while maintaining a nearly horizontal upward position.

[0009] Furthermore, the board cutting apparatus to which the workpiece feeding and returning device described in claim 4 is applied is A raw material lifter device for supplying raw material workpieces to the processing position, This material receiving conveyor receives the material workpieces transferred from the material lifting device, A lip cutting machine that cuts raw material into long workpieces with a desired width, A long workpiece transport conveyor for transferring this long workpiece to the next stage, In addition to this long workpiece delivery conveyor, there is a long workpiece receiving conveyor whose delivery direction is set to an appropriate direction, A board cutting device comprising a cross-cutting machine provided in the forward direction of the transfer of a long workpiece receiving conveyor is characterized in that the board cutting device is adapted to the workpiece return device described in any one of claims 1 to 3. [Effects of the Invention]

[0010] First, according to the invention described in claim 1, the extrusion chuck unit, which is holding the rear end of a long workpiece, can be slightly raised together with the lifting frame simply by releasing the pressure (operating pressure) on the lifting shift cylinder. Therefore, it is not necessary to use a dedicated actuator or the like to slightly raise the lifting frame.

[0011] Furthermore, according to the invention described in claim 2, a compression coil spring can be applied as a specific biasing means.

[0012] Furthermore, according to the invention described in claim 3, when the extrusion chuck unit holds the rear end of a long workpiece, the extension arm, which moves up and down integrally with the chuck plate, descends while maintaining a nearly horizontal upward position, thus ensuring that the rear end of the long workpiece is held securely.

[0013] Furthermore, according to the invention described in claim 4, a series of processes can be carried out rationally and efficiently, which involves cutting a long workpiece of a certain width from a board-shaped raw material, and then cutting this long workpiece into appropriate lengths (shorter pieces) to obtain intermediate workpieces. [Brief explanation of the drawing]

[0014] [Figure 1] It is a perspective view schematically showing a board cutting device to which the work feed and return device of the present invention is applied. [Figure 2] It is a perspective view showing a long work receiving conveyor part in a board cutting device. [Figure 3] It is a perspective view showing the work feed and return device of the present invention. [Figure 4] It is a perspective view showing the periphery of a biasing means provided between a traveling beam and a lifting base. [Figure 5] It is a side view showing a lifting base and an extrusion chuck unit. [Figure 6-1] It is an explanatory view showing an operating mode (first stage) when holding (grasping) the rear end portion of a long work. [Figure 6-2] It is an explanatory view showing an operating mode (second stage) when holding (grasping) the rear end portion of a long work. [Figure 6-3] It is an explanatory view showing an operating mode (third stage) when holding (grasping) the rear end portion of a long work. [Figure 7] It is explanatory views (a) and (b) showing step by step how an intermediate work is individually transferred to the next process by a scraping device applied to a board cutting device.

Embodiment for Carrying Out the Invention

[0015] The embodiment for carrying out the present invention is as shown in the following examples, but appropriate modifications can also be made within the scope of the technical idea of the present invention with respect to these examples.

Examples

[0016] First, prior to a specific description of the "work feed and return device 2 in a board cutting device" (hereinafter, may also be simply referred to as "work feed and return device 2") of the present invention, an overview of the overall operation (actuation) of the board cutting device 1 from a raw material work W to a long work W1 and further to an intermediate work W2 from the long work W1 will be given.

[0017] As an example, the board cutting device 1 includes a raw material lifter device 11 for supplying raw material workpieces W to the processing position, and a raw material receiving conveyor 12 is provided in conjunction with the raw material lifter device 11. A lip cutting machine 13, which is essentially a running saw, is provided downstream of the raw material receiving conveyor 12. Furthermore, a long workpiece delivery conveyor 14 is provided downstream of the lip cutting machine 13, and a long workpiece receiving conveyor 15 is provided, with the delivery direction set, for example, perpendicular to the long workpiece delivery conveyor 14. Furthermore, a cross cutting machine 16, which is essentially a running saw, is provided in front of the long workpiece receiving conveyor 15 in the direction of transport. In addition, an intermediate workpiece removal table 17 is provided downstream of the cross cutting machine 16, and a removal conveyor 18 is provided on the forward side in the direction of delivery.

[0018] Under this arrangement of the devices, the raw material workpieces W are cut sequentially. The raw material workpieces W are, for example, boards with dimensions of approximately 1 meter in width and 2 to 3 meters in length. These are sent from the raw material receiving conveyor 12 to the lip cutting machine 13 and cut into long workpieces W1 with the desired width. For example, a turntable can be placed in the center of the raw material receiving conveyor 12. In this case, the incoming raw material workpieces W can be held in both the longitudinal and transverse directions (long side and short side), and this operation allows for efficient material extraction from the raw material workpieces W.

[0019] In this way, the long workpiece W1 cut by the lip cutting machine 13 is transported by the long workpiece delivery conveyor 14. The transfer from the lip cutting machine 13 to the long workpiece delivery conveyor 14 is done by pushing the remaining raw material workpiece W into the lip cutting machine 13, and the pushing end of the machine pushes out the already cut long workpiece W1, thereby transferring it to the long workpiece delivery conveyor 14. After that, the long workpiece W1 is further transferred to the long workpiece receiving conveyor 15 and supplied to the subsequent cross cutting machine 16 by the workpiece return device 2 according to the present invention. The cross cutting machine 16 forms a saw path perpendicular to the workpiece feeding direction by 90 degrees, and the cross cutting machine 16 sequentially cuts the long workpiece W1 into appropriate lengths from its front end (front end in the direction of movement) according to the set dimension specifications.

[0020] Incidentally, the intermediate workpiece W2 cut by the cross-cutting machine 16 was conventionally transported onto the intermediate workpiece removal table 17 by being pushed out by the progress (forward movement) of the next long workpiece W1 to be cut. However, if the pushing is simply done by the long workpiece W1 to be cut in the next cycle, the pushing position is not always consistent, and when the intermediate workpiece W2 is subsequently stacked by, for example, a manipulator M, this stacking operation cannot be carried out smoothly. To address this situation, the applicant has separately developed a workpiece scraping device. Specifically, the applicant has proposed a scraping device 7 (scraping unit) that can accurately transport the intermediate workpiece W2 cut by the cross-cutting machine 16 from the intermediate workpiece removal table 17 to the removal conveyor 18.

[0021] Specifically, as shown in Figures 7(a) and 7(b) as an example, the scraping method involves cutting with the cross-cutting machine 16 to form a cutting gap SL between the obtained intermediate workpiece W2 and the remaining long workpiece W1, which is roughly equal to the blade thickness of the saw blade 161. First, the scraping body 71 of the scraping device 7 is inserted into this cutting gap SL. This causes the scraping body 71 to be pressed against the end face of the intermediate workpiece W2 that is being cut. In this state, the scraping device 7 can be moved forward, allowing the intermediate workpieces W2 to be moved forward individually. Here, for example, if the remaining long workpiece W1 moves slightly immediately after cutting, it may be difficult to insert the scraping body 71 into the cutting gap SL. To ensure this insertion is successful, the remaining long workpiece W1 after the intermediate workpiece W2 has been cut is slightly pulled back by the workpiece feeding return device 2 according to the present invention, essentially being slightly retracted. Then, once the intermediate workpiece W2 has been successfully moved forward by the scraping device 7, the remaining long workpiece W1 is pushed forward again by the workpiece return device 2 and moves forward by the specified dimensions in preparation for the next cut (cutting by the cross-cutting machine 16).

[0022] The following will specifically describe the workpiece feeding and returning device 2, which is responsible for the above-mentioned function, namely, the function of slightly pulling back the long workpiece W1 that has been cut by the cross-cutting machine 16. As an example, the workpiece feeding and returning device 2 includes, as shown in Figures 2 to 5, a traveling beam 3 as its main component, a lifting frame 4 supported by the traveling beam 3, and an extrusion chuck unit 5 supported by the lifting frame 4 and directly supporting the long workpiece W1. First, let me explain the travel beam 3. The traveling beam 3 travels on the rail 101 on the frame F of the board cutting device 1, with the linear bearing block on the traveling beam 3 moving along the rail 101. The traveling beam 3 is configured such that a pinion gear 31 provided on it meshes with a rack (not shown) provided on the frame F, and by driving this pinion gear 31, the traveling beam 3 moves as a whole in the front-rear direction. The travel beam 3, although not shown in the diagram, is a structural member that incorporates motors, power supply piping, air piping, and auxiliary equipment such as control valves for driving the equipment mounted on it. Furthermore, the travel beam 3 is equipped with, for example, four vertically elongated plate-shaped frame support brackets 32 arranged in parallel (side-by-side). Each frame support bracket 32 ​​has a cylinder support plate 33 that protrudes forward from its upper end, a lower stopper piece 34 at its lower end, and a vertically elongated lifting guide rail 35 between them. Above the cylinder support plate 33, a vertically positioned lifting shift cylinder 36 is provided, and this lifting shift cylinder 36 is equipped with a downward-facing lifting rod 36a. By extending and retracting the lifting rod 36a of the lifting shift cylinder 36, the lifting frame 4, which will be described next, is raised and lowered.

[0023] Next, I will explain the lifting platform 4. The lifting frame 4 is a frame member that supports the extrusion chuck unit 5, which will be described later, and moves it up and down in the vertical direction. In other words, it refers to the frame member that moves up and down, excluding the components of the extrusion chuck unit 5. The lifting platform 4 is equipped with four vertically elongated plate-shaped lifting bases 40, each corresponding to one of the four platform holding brackets 32. A slider block 41 is provided on the rear of each lifting base 40, and the lifting platform 4 (lifting base 40) is configured to slide up and down, guided by a lifting guide rail 35 provided on the platform holding brackets 32. Furthermore, these four lifting bases 40 are integrally connected by a cross frame 42 arranged horizontally. Each lifting base 40 is equipped with a rod connecting piece 40a at its upper end, to which the lower end of the lifting rod 36a of the lifting shift cylinder 36 is connected. On the other hand, at the lower part of the lifting base 40, for example as shown in Figure 4 above, a stopper contact piece 43 is formed to protrude so as to overlap the upper part of the lower stopper piece 34. Between the lower stopper piece 34 and the stopper contact piece 43, a biasing means S is provided, for example, using a coil spring. Furthermore, the lifting base 40 has four unit support arms 44 arranged side by side, which protrude forward (see Figure 3). Each unit support arm 44 consists of a pair of left and right plate-like members and a bottom plate member, and is configured in a narrow channel shape, that is, a U-shape in cross-section when viewed from the front and rear direction (with the open part of the U-shape facing upwards).

[0024] Each of these four unit support arms 44 is equipped with a rod support block 45 inside the two outermost unit support arms 44 (the two on each side), and a cylinder support block 46 is provided outside the two inner unit support arms 44. Furthermore, the lifting base 40 is equipped with a chuck cylinder support plate 47. The chuck cylinder support plate 47 is positioned above the base of the unit support arm 44 in a floating manner. In a plan view, a pair of mounting rods, or support legs 48, extend downward from the front and rear of the chuck cylinder support plate 47, and their lower ends are fixed to the bottom plate member of the unit support arm 44 (see Figure 6-1). Furthermore, as shown in Figure 6-2 as an example, a slidable guide sleeve 48a is provided on the outer circumference of the support legs 48 in an externally fitted state. This guide sleeve 48a slides together with the extension arm 56, allowing the extrusion chuck unit 5, described later, to move downward while maintaining a nearly horizontal upward position.

[0025] Next, we will describe the extrusion chuck unit 5. The extrusion chuck unit 5 primarily holds (gripped) the rear end of the long workpiece W1 that has been supplied to the long workpiece receiving conveyor 15. The extrusion chuck unit 5 has an extrusion plate 51 that is responsible for the extrusion action of the long workpiece W1, and lower pressing claws 54 and a chuck plate 55 that grip the rear end of the long workpiece W1 from above and below as its direct working members. Of these, the extrusion plate 51 is provided across the entire working width of the workpiece feeding and returning device 2, as shown in Figure 3 above, for example, and two guide rods 52 extending in the rearward direction are slidably supported in the front-rear direction by the rod support block 45. In addition, as a means for moving the extrusion plate 51 back and forth in the front-rear direction, two extrusion cylinders 53 are provided parallel to the guide rods 52, and the extrusion cylinders 53 are horizontally arranged in the front-rear direction by the cylinder support block 46. The extrusion rods 53a of these extrusion cylinders 53 are connected to the rear end of the extrusion plate 51.

[0026] Furthermore, the lower retaining claw 54 is provided at the tip of the unit support arm 44 on the lifting frame 4 so as to protrude forward. Opposite to the lower retaining claw 54, a pair of chuck plates 55 are provided above it so as to be able to move up and down, and are configured to hold the rear end of the long workpiece W1 between them when the chuck plates 55 are lowered. The chuck plates 55, like the extrusion plate 51, are provided across the entire operating width of the workpiece feeding and returning device 2. The chuck plate 55 is attached to the tip of the extension arm 56, and the extension arm 56 has a connection portion 56a for the chuck shift rod 57a of the chuck cylinder 57 near its rear end, and is equipped with multiple guide sleeves 48a in the front-rear direction (in this case, a pair front and rear) to maintain (regulate) the posture during raising and lowering. The chuck cylinder 57 for raising and lowering the chuck plate 55 is mounted on the chuck cylinder support plate 47 with the chuck shift rod 57a facing downward, and the chuck shift rod 57a is provided to pass through the chuck cylinder support plate 47 and extend downward therefrom. In this specification, "maintaining an upward posture (downward movement)" and "maintaining posture (restriction)" refer to the extension arm 56 descending (moving up and down) while maintaining a nearly horizontal posture, while being sandwiched between the left and right plate-shaped members of the unit support arm 44.

[0027] The following describes the arrangement of the extrusion plate 51 and the chuck plate 55. When the extrusion plate 51 is in a standby position where it does not protrude forward, the operating position of the chuck plate 55 is further forward. Therefore, to avoid interference with the extrusion plate 51 when the chuck plate 55 and the extension arm 56 supporting it move downward, and to allow the chuck plate 55 to be lowered sufficiently, the extrusion plate 51 has a relief portion 51a formed at a position corresponding to the extension arm 56 (see Figure 3).

[0028] The workpiece feeding and returning device 2 of the present invention has the basic configuration described above and operates as follows to push the long workpiece W1 forward and pull it back slightly backward, i.e., to perform a slight retraction. [1] Standby state First, the standby state of the workpiece return device 2 is the state before receiving the long workpiece W1, and this state will be explained. That is, in this standby state, the receiving zone 15Z of the long workpiece receiving conveyor 15 in the workpiece return device 2 is empty, and in preparation for receiving the long workpiece W1, the workpiece return device 2 is positioned in the standby zone FZ of the frame F that extends further rearward from the rear end of the long workpiece receiving conveyor 15 (see Figure 2). At this time, the lifting platform 4 is not at its bottom dead center, but is at least somewhat higher than the top surface of the long workpiece W1, and the chuck plate 55 is also waiting at a position raised somewhat above the top surface of the long workpiece W1. Next, the long workpiece W1, which has been cut in the previous lip cutting machine 13, is sent from the long workpiece delivery conveyor 14 to the receiving zone 15Z of the long workpiece receiving conveyor 15, as shown in Figure 2 above as an example.

[0029] [2] Holding long workpieces Subsequently, the long workpiece W1, which has been transferred to the receiving zone 15Z, is held (gripped) by its rear end by the extrusion chuck unit 5 in the workpiece feeding return device 2. This operation begins with the lifting frame 4 receiving the downward extension of the lifting rod 36a in the lifting shift cylinder 36, causing it to descend to the position of the long workpiece W1 (bottom dead center). That is, this descent brings the upper surface of the lower holding claw 54 and the lower surface of the long workpiece W1 to approximately coincide. Also, at this bottom dead center, as shown in Figure 6-2(a) as an example, the spring, which is the biasing means S, is in a compressed state. Next, the pinion gear 31 of the travel beam 3 is driven, causing the workpiece feeding and returning device 2 to move slightly forward to a position where it can hold the rear end of the long workpiece W1. In this state, the chuck plate 55 remains in its raised position. Subsequently, as shown in Figure 6-2(c) as an example, the chuck plate 55 descends, and the rear end of the long workpiece W1 is held (gripped) between the lower retaining claws 54 and the chuck plate 55 from above and below. This holding operation is performed by the downward extension of the chuck shift rod 57a of the chuck cylinder 57. At this time, two support legs 48 extending downward from the chuck cylinder support plate 47 of the chuck cylinder 57 have slidable guide sleeves 48a fitted to their outer circumferences. These guide sleeves 48a descend (move up and down) together with the chuck plate 55 (extension arm 56), so the extension arm 56 of the extrusion chuck unit 5 descends while maintaining a nearly horizontal upward position.

[0030] [3] Advancement of long workpieces In this state, the pinion gear 31 of the travel beam 3 is driven again, causing the long workpiece W1 to move forward by the required distance, beyond the position of the cross-cutting machine 16 (the saw path which will be the cutting trajectory). During this forward movement, the long workpiece W1 is gripped by the lower holding claws 54 and the chuck plate 55, and the rear end of the long workpiece W1 is in contact with and being pushed by the extrusion plate 51. At this time, of course, the cross-cutting machine 16 is retracted to a position where it does not interfere with the transport path of the long workpiece W1.

[0031] [4] Cutting of long workpieces using a cross-cutting machine Subsequently, as shown in Figure 7(a) as an example, the front portion of the long workpiece W1 is cut to the desired length by the saw blade 161 of the cross-cutting machine 16, obtaining an intermediate workpiece W2. This cutting creates a cutting gap SL between the cut intermediate workpiece W2 and the remaining long workpiece W1, with a gap approximately equal to the tooth thickness (blade width) of the saw blade 161.

[0032] [5] Slight retraction of long workpiece The intermediate workpieces W2, having been cut in this manner, are then individually transferred to the next process and are moved on the intermediate workpiece removal table 17 by the scraping body 71 of the scraping device 7. At this time, in order for the scraping body 71 to be reliably applied to the end face of the intermediate workpiece W2 to be cut, it is preferable to widen the cutting gap SL, and for this purpose the remaining long workpiece W1 is slightly retracted. This slight retraction is necessary because, if the remaining long workpiece W1 is left as is on the long workpiece receiving conveyor 15, the sliding resistance (frictional resistance) when moving the long workpiece W1 becomes excessive, and the holding force of the lower pressing claws 54 and chuck plate 55 alone is generally insufficient to pull the long workpiece W1 back. For this reason, prior to pulling the long workpiece W1 back, as an example, as shown in Figure 6-3(e), the rear end of the long workpiece W1 is slightly raised, creating a state in which only the front end of the long workpiece W1 is in contact with the long workpiece receiving conveyor 15. In this case, as shown in Figures 6-3(c) to (d), for example, the operating pressure (pneumatic or hydraulic) of the lifting shift cylinder 36 is released, and the biasing means S provided between the lower stopper piece 34 on the travel beam 3 side and the stopper contact piece 43 on the lifting frame 4 side pushes the lifting frame 4 slightly upward. Thus, in this invention, the downward pushing of the lifting frame 4 is released simply by releasing the operating pressure to the lifting shift cylinder 36, without using any other actuators to slightly raise the lifting frame 4, and the extrusion chuck unit 5 holding the rear end of the long workpiece W1 can be slightly raised together with the lifting frame 4. Then, the long workpiece W1 is slightly retracted by slightly retracting the travel beam 3, and the cutting gap SL can be widened.

[0033] [6] Extrusion of workpiece scraps If the above processing steps are continued, so-called scrap material may be generated from the remaining part of the workpiece where the required dimensions cannot be obtained. To address this situation, the extrusion plate 51 in the extrusion chuck unit 5 moves forward, dropping the scrap material into the scrap material receiving section (not shown) at the front. In other words, the scrap material receiving section is configured to tilt and release a part of the intermediate workpiece removal table 17 at the front of the cross-cutting machine 16, and the extrusion plate 51 pushes the workpiece scrap material to that section and removes it. Of course, at this time, the chuck plate 55 is moved to a retracted position upward by retracting the chuck cylinder 57 to allow the extrusion plate 51 to move forward.

[0034] [7] Acceptance of workpieces for next processing To improve processing efficiency, as processing of the long workpiece W1 progresses, the long workpiece W1 to be processed in the next cycle can be received by the long workpiece receiving conveyor 15. That is, as processing of the long workpiece W1 currently being processed progresses and the remaining length decreases, the receiving zone 15Z of the long workpiece receiving conveyor 15 becomes empty. In this state, the long workpiece W1 to be processed next can be received from the long workpiece delivery conveyor 14. Then, the next long workpiece W1 (the long workpiece W1 to be processed in the next cycle) is supplied from the long workpiece delivery conveyor 14. The workpiece return device 2, which has finished processing the previous cycle, can then retract the lifting shift cylinder 36, raise the lifting frame 4 sufficiently, and return to the starting position while passing over the newly supplied long workpiece W1. After this, the previously described process is continued.

[0035] ◇Example of modification [Other examples] While the present invention is based on the embodiments described above as one basic technical concept, the following further modifications are conceivable. First, in the basic embodiment described above, a compression coil spring is used as the biasing means S. However, various biasing means S can be applied within the range in which the lifting platform 4 can be raised when the pressure of the lifting shift cylinder 36 is released. Specifically, for example, a tension-type spring, a torsion bar-type spring, a diaphragm-type spring, and even a rubber block with shape recovery properties can be applied. [Explanation of symbols]

[0036] 1. Board cutting device 2. Workpiece feeding and return device 3. Travel beam 4. Lifting platform 5. Extrusion Chuck Unit 7. Scraping device 11. Raw material lifter device 12. Raw material receiving conveyor 13 Lip cutting machine 14. Long workpiece delivery conveyor 15. Long workpiece receiving conveyor 15Z Pickup Zone 16 Cross-cutting machine 17 Intermediate workpiece retrieval table 18. Take-out conveyor 31 Pinion Gear 32 Mounting bracket 33 Cylinder support plate 34 Lower stopper piece 35 Lifting guide rails 36 Lifting / Lowering Shift Cylinder 36a Lifting rod 40 Lifting base 40a Rod connecting piece 41 Slider Blocks 42 Cross Frame 43 Stopper contact piece 44 Unit Support Arms 45 Rod support block 46 Cylinder support block 47 Chuck cylinder support plate 48 Support legs (mounting rods) 48a Guide Sleeve 51 Extruded sheet 51a Escape Department 52 Guide Rods 53 Extrusion Cylinder 53a Extrusion rod 54 Lower pressing claw 55 Chuck plate 56 Extension Arm 56a Connection 57 Chuck Cylinder 57a Chuck shift rod 71 Scraping main body 101 Rail 161 saw blade F Frame FZ Waiting Zone M Manipulator S biasing means SL cutting gap W Raw Material Work W1 Long Workpiece W2 Intermediate Work

Claims

1. A workpiece feeding and retraction device that, when cutting a long workpiece into shorter lengths, pushes the rear end of the long workpiece to feed the leading end of the long workpiece to the cutting position, and at the same time holds and pulls back the remaining rear end of the long workpiece after cutting, causing it to retract slightly backward, This workpiece feeding and return device is A traveling beam supported by a frame and moving in the workpiece feeding direction, This lifting platform is supported by a travel beam and is raised and lowered by a lifting shift cylinder, This system comprises an extrusion chuck unit supported on a lifting platform, This extrusion chuck unit is An extruded plate supported by a unit support arm on a lifting platform, which can freely protrude forward, A chuck plate that can move freely in the vertical direction, This chuck plate is equipped with a lower retaining claw located below it. The workpiece feeding and returning device in a board cutting device is characterized in that the lifting platform is provided with a biasing means between the lifting platform and the travel beam, which slightly raises the lifting platform when the pressure of the lifting shift cylinder is released.

2. The workpiece feeding and returning device in a board cutting device according to claim 1, characterized in that the biasing means is a compression coil spring, the lower end surface of which is supported on the travel beam side, and biases the lifting frame upward.

3. The chuck plate is attached to the front side of an extension arm that is configured to move up and down relative to the unit support arm. Furthermore, the lifting platform comprises a plurality of support legs provided in the front-rear direction, and guide sleeves provided on the outer circumference thereof to be slidable. Of these, the support legs are provided to connect the chuck cylinder support plate and the bottom plate member of the unit support arm. When lowering the chuck plate and holding the rear end of the long workpiece between the chuck plate and the lower clamping jaws, The workpiece feeding and returning device in a board cutting device according to claim 1 or 2, characterized in that, as the extension arm descends, the guide sleeve slides downward on the outer circumference of the support leg, thereby causing the extension arm to descend while maintaining a nearly horizontal upward position.

4. A raw material lifter device for supplying raw material workpieces to the processing position, This material receiving conveyor receives the material workpieces transferred from the material lifting device, A lip cutting machine that cuts raw material into long workpieces with a desired width, A long workpiece transport conveyor for transferring this long workpiece to the next stage, In addition to this long workpiece delivery conveyor, there is a long workpiece receiving conveyor whose delivery direction is set to an appropriate direction, A board cutting device comprising a cross-cutting machine provided in the forward direction of the transfer of a long workpiece receiving conveyor, wherein the board cutting device is characterized in that it applies the workpiece feeding and returning device described in any one of claims 1 to 3.

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