Manufacturing device and manufacturing method of cushion rubber for cargo reception table lifting device

Abstract

To provide a manufacturing device and a manufacturing method of a cushion rubber for a cargo reception table lifting device capable of forming a bolt hole having a desired shape with high position accuracy with respect to a rubber plate.SOLUTION: A manufacturing device of a cushion rubber for a cargo reception table lifting device includes: a table on which a long rubber plate is placed; a clamp mechanism sandwiching the rubber plate placed on the table in a width direction of the rubber plate; a drill mechanism that perforates the rubber plate sandwiched by the clamp mechanism with a drill; and a pressing mechanism that presses the rubber plate sandwiched by the clamp mechanism against the table by pressing the rubber plate in the perforation direction of the drill.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a manufacturing device and a manufacturing method for cushion rubber for a load-receiving platform lifting device. [Background technology]

[0002] BACKGROUND ART There is a drilling device that clamps and presses a long object made of wood, resin, metal, or the like, and drills holes in the long object in a direction perpendicular to the pressing direction of the clamp (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-71205 Summary of the Invention [Problem to be solved by the invention]

[0004] Cushion rubber is sometimes attached to the underside of the receiving platform of a receiving platform lifting device in the area that comes into contact with the ground. This cushion rubber is manufactured by drilling bolt holes in a long rubber plate to secure it to the receiving platform. However, the long rubber plate into which the bolt holes are drilled is stored in a rolled state for a certain period of time, and may become wavy when it is unfolded and drilled. Therefore, the manufactured cushion rubber may have slight variations in the shape, position, and orientation of the bolt holes depending on the degree of undulation of the rubber plate during drilling.

[0005] However, even slight variations in the position of the bolt holes in the cushion rubber may prevent the cushion rubber from being fixed to the load receiving platform in the desired state. For example, if the bolt hole pitch is larger than the design value and the cushion rubber is attached to the load receiving platform in a slightly deflected state, the durability of the cushion rubber may decrease, and subsequent repeated contact with the ground may accelerate the progression of deterioration. The cushion rubber must be fixed in good surface contact with the load receiving platform, with the bolts inserted precisely in the desired positions and with the appropriate tension applied.

[0006] An object of the present invention is to provide a manufacturing device and a manufacturing method for cushion rubber for a load-receiving platform lifting device, which are capable of drilling bolt holes of a desired shape in a rubber plate with high positional accuracy. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention provides a manufacturing device for cushion rubber for a load-receiving platform lifting device, which includes a table on which a long rubber plate is placed, a clamping mechanism that clamps the rubber plate placed on the table in the width direction of the rubber plate, a drilling mechanism that drills holes in the rubber plate clamped by the clamping mechanism, and a pressing mechanism that presses the rubber plate clamped by the clamping mechanism in the drilling direction against the table. [Effects of the Invention]

[0008] According to the present invention, bolt holes of a desired shape can be drilled in a rubber plate with high positional accuracy in the manufacture of cushion rubber for a platform lifting device. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a side view showing a schematic representation of a vehicle equipped with an example of a loading platform lifting device that uses cushion rubber manufactured by a manufacturing apparatus according to an embodiment of the present invention. [Figure 2]1 is a perspective view of an example of a loading platform lifting device to which a cushion rubber manufactured by a manufacturing apparatus according to an embodiment of the present invention is applied. [Figure 3] 1 is a rear view of an example of a loading platform lifting device to which cushion rubber manufactured by a manufacturing apparatus according to an embodiment of the present invention is applied. [Figure 4] 1 is a side view of an example of a loading platform lifting device to which cushion rubber manufactured by a manufacturing apparatus according to an embodiment of the present invention is applied. [Figure 5] 1 is a perspective view of a cushion gum manufacturing device according to an embodiment of the present invention. [Figure 6] 1 is a front view of a cushion gum manufacturing device according to an embodiment of the present invention. [Figure 7] 1 is a plan view of a cushion gum manufacturing device according to an embodiment of the present invention. [Figure 8] 8 is a side view of the clamp mechanism as seen from the arrow AA in FIG. 7. [Figure 9] 9 is a cross-sectional view of the clamp mechanism taken along the arrow BB in FIG. 8. [Figure 10] 9 is a cross-sectional view of the clamp mechanism taken along the CC arrow in FIG. 8. [Figure 11] 1 is a perspective view of a pressing mechanism provided in a cushion gum manufacturing device according to an embodiment of the present invention. FIG. [Figure 12] FIG. 10 is a schematic diagram of a clamping mechanism according to a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] -vehicle- 1 is a side view showing a vehicle equipped with an example of a platform lifting / lowering device that uses cushion rubber manufactured by a manufacturing apparatus according to one embodiment of the present invention. In this embodiment, an example will be described in which a vertical platform lifting / lowering device 100 is mounted on the rear of a platform LP mounted on a chassis frame F (FIG. 3) of a vehicle V. In addition, in this specification, the left and right in FIG. 1 refer to the front and rear of the vehicle V and the platform lifting / lowering device 100.

[0012] -Load receiving platform lifting device- Fig. 2 is a perspective view of an example of a loading platform lifting device that uses cushion rubber manufactured by a manufacturing apparatus according to one embodiment of the present invention, Fig. 3 is a rear view, and Fig. 4 is a side view. Fig. 2 shows the loading platform 4 in an unfolded state, and Figs. 3 and 4 show the loading platform 4 in a stored state. Figs. 3 and 4 also show the lower part of the loading platform lifting device. In these figures, elements corresponding to those in previously mentioned figures are given the same reference numerals as those in the previously mentioned figures, and explanations thereof will be omitted where appropriate.

[0013] The loading platform lifting device 100 includes posts 1L, 1R, sliders 3L, 3R, a loading platform 4, a cross member 5, a hydraulic cylinder 6, and a power unit 9. Each element will be described below in order.

[0014] ·post The posts 1L, 1R are located at both the left and right ends of the rear end of the loading platform LP of the vehicle V and extend vertically. These left and right posts 1L, 1R are hollow, for example, made of square pipes. The front space inside the posts 1L, 1R is called the front chamber 1a, and the rear space is called the rear chamber 1b. The front chamber 1a and the rear chamber 1b are separated by a partition wall, except for the upper part. The rear wall of the rear chamber 1b has a slit 1d (Figure 2) that extends vertically. The posts 1L, 1R are also provided with hooks 1f. The hooks 1f are non-movable fixed structures. The loading platform lifting device 100 is equipped with a bumper 1X that connects the lower parts of the left and right posts 1L, 1R. The bumper 1X has a rectangular prism shape that extends horizontally and is made of, for example, a square pipe with sufficient strength.

[0015] Slider The sliders 3L, 3R extend vertically and are inserted into the rear chambers 1b of the posts L1, LR via sub-posts (not shown), respectively, and move vertically inside the rear chambers 1b. The rear portions of the sliders 3L, 3R protrude rearward from the posts 1L, 1R through slits 1d in the posts 1L, 1R. A bracket 3b is provided on the lower portion of the rear portions of the sliders 3L, 3R that protrude rearward from the posts 1L, 1R. The sub-posts may be omitted.

[0016] Loading platform The receiving platform 4 is rotatably connected to the brackets 3b of the sliders 3L and 3R via pins 4a, and is raised and lowered together with the sliders 3L and 3R, guided by subposts (not shown) and posts 1L and 1R. The receiving platform lifting device 100 illustrated in FIG. 2 is a high-lift type, and the lifting range of the receiving platform 4 exists not only below the floor level but also above the floor level. The floor level refers to the height position of the receiving platform 4 where the receiving surface (top surface) is aligned with the floor of the loading platform LP and the top surface of the cross member 5. The receiving platform 4 can be raised and lowered across the floor level of the loading platform LP, i.e., above and below the floor level. When not in use, the receiving platform 4 can be raised vertically to form the rear wall (tailgate) of the loading platform LP. When in a horizontally tilted position, the receiving platform 4 can be raised and lowered with cargo, workers, etc. on it during loading and unloading operations. Lock handles 4b (only the left one is shown in Figure 2) are provided on both the left and right sides of the receiving platform 4. The receiving platform 4 is moved to a storage position at a predetermined height (in this example, the floor level of the platform LP) and raised, and the lock handles 4b are pulled out to the left and right and hooked onto the hooks 1f, whereby the receiving platform 4 is fixed (stored) in an upright position relative to the posts 1L, 1R.

[0017] As shown in FIG. 4 , a cushion rubber CR is fixed to the back surface of the load receiving platform 4 (the contact surface behind the load receiving surface) with bolts B. In this embodiment, the cushion rubber CR has a plurality of bolt holes (not shown) spaced apart in the longitudinal direction through which the bolts B pass. These bolt holes are arranged along the edges of the main surface of the cushion rubber CR, and the bolt holes located at the ends of the cushion rubber CR in the longitudinal direction are located at the corners (four corners) of the cushion rubber CR. In this embodiment, a configuration is illustrated in which cushion rubber CR formed by cutting into a long flat bar is provided on the contact surfaces of the horizontal stiffeners 4c and vertical stiffeners 4d on the back surface of the load receiving platform 4, but cushion rubber CR cut into short blocks may also be provided on the four corners of the back surface of the load receiving platform 4.

[0018] Cross member The cross member 5 extends left and right and connects the vertical middle portions of the posts 1L, 1R. The cross member 5 is hollow, and its internal space is connected to at least the front chambers 1a of the posts 1L, 1R. When the loading platform lifting device 100 is mounted on the vehicle V, the cross member 5 is located above the chassis frame F (Figure 3) of the vehicle V, and the top surface of the cross member 5 is flush with the floor surface of the loading platform LP.

[0019] Hydraulic cylinder The hydraulic cylinder 6 is a drive device that drives the load-receiving platform 4 to move up and down, and is housed in the cross member 5 in an orientation extending from side to side. The hydraulic cylinder 6 can also be installed with its rod facing left, but in this embodiment, it is installed with its rod facing right, with its tube fixed to the inner wall of the cross member 5 via a support member. The tip of the rod of the hydraulic cylinder 6 moves back and forth left and right inside the cross member 5 as the hydraulic cylinder 6 extends and retracts. The extension and contraction of this hydraulic cylinder 6 operates a wire (not shown) that is looped around multiple pulleys (fixed pulleys, movable pulleys) and routed inside the posts 1L, 2R and the cross member 5. This causes sliders 3L, 3R fixed to the wire to move up and down, and the load-receiving platform 4 moves up and down.

[0020] Power unit The power unit 9 is a power device that drives the hydraulic cylinder 6, and is configured to include, for example, an electric motor, a hydraulic pump, an oil tank, a switching valve, a control device, etc. In the example of FIG. 2, it is housed in a unit box 9a provided in front of the left post 1L. Note that the power unit 9 is not shown in the drawings other than FIG. 2.

[0021] -Cushion rubber manufacturing equipment- Fig. 5 is a perspective view of a cushion gum manufacturing apparatus 10 according to one embodiment of the present invention, Fig. 6 is a front view, and Fig. 7 is a plan view. Fig. 8 is a side view of the clamp mechanism 30 taken along the line AA in Fig. 7, Fig. 9 is a cross-sectional view of the clamp mechanism 30 taken along the line BB in Fig. 8, Fig. 10 is a cross-sectional view of the clamp mechanism 30 taken along the line CC in Fig. 8, and Fig. 11 is a perspective view of a pressing mechanism 50 provided in the cushion gum manufacturing apparatus 10.

[0022] The cushion rubber manufacturing device 10 shown in these figures is a device for manufacturing cushion rubber CR for the load receiving platform of the load receiving platform lifting device as shown in Fig. 4. The cushion rubber manufacturing device 10 manufactures cushion rubber CR by drilling bolt holes in a long rubber plate W (Fig. 10) of, for example, several meters, and then cutting the rubber plate to the desired length. The rubber plate W is formed into a long flat bar shape by unrolling the material in a roll and cutting it to the desired width (for example, around 20 cm to 2 m).

[0023] 5 includes a table 20 on which a long rubber sheet W is placed, a clamping mechanism 30 that clamps the rubber sheet W placed on the table 20 in the width direction (short direction) of the rubber sheet W, a drilling mechanism 40 that drills holes in the rubber sheet W clamped by the clamping mechanism with a drill 41, a pressing mechanism 50 that presses the rubber sheet W clamped by the clamping mechanism 30 against the table 20 in the drilling direction of the drill 41 (downward in this embodiment), and a control device 60 that controls the clamping mechanism 30, the drilling mechanism 40, and the pressing mechanism 50. The main body of the cushion rubber manufacturing device 10, which is made up of the table 20, the clamping mechanism 30, the drilling mechanism 40, the pressing mechanism 50, etc., excluding the control device 60, is surrounded by a fence 12. Part of the fence 12, which in this embodiment is the front side of the cushion rubber manufacturing apparatus 10, is made up of a shutter 13, and an operator opens the shutter 13 to access the main body of the cushion rubber manufacturing apparatus 10 and perform tasks such as setting the rubber sheet W, collecting the cushion rubber CR, and replacing jigs including the clamps of the clamping mechanism 30. Figure 5 shows the shutter 13 in a closed (raised) state, and Figure 6 shows the shutter 13 in an open (lowered) state.

[0024] -table- The table 20 includes a base plate 21 and a bed 22 placed on the base plate 21. The base plate 21 is a flat member fixed to the top of the clamp mechanism 30 and has multiple slits through which clamp bar fasteners 35 (described later, not shown) pass. These slits extend in the short direction of the rubber plate W to be placed thereon (the left-right direction in FIG. 10 in this embodiment). The bed 22 is a plate-like member slightly narrower than the rubber plate W. The bed 22 can have multiple widths depending on the width of the rubber plate W (i.e., the dimensions of the cushion rubber CR). FIG. 10 illustrates a configuration in which three beds 22 are arranged in rows. The rubber plate W is placed on the table 20 via these beds 22. The rubber plate W extends in a direction perpendicular to the plane of FIG. 10 (for example, the left-right direction in FIG. 7) and is set on the table 20 with its two widest principal surfaces facing up and down.

[0025] -Clamping mechanism- As shown in Fig. 10, the clamping mechanism 30 includes a frame 31, a stopper 32, a clamp bar 33, and an air cylinder 34. The frame 31 is a box-shaped member that is open at the top. The table 20 is fixed to the top of the frame 31, and the top opening of the frame 31 is closed by the table 20. The frame 31 is fixed to the base 11 of the cushion gum manufacturing apparatus 10 by a plurality of vises 39 (Fig. 7) that are made up of air clamps. The stopper 32 is fixed to the upper surface of the base plate 21 of the table 20. The stoppers 32 are square bars that extend linearly along the rubber sheet W placed on the table 20, and in this embodiment, they are arranged in three rows at regular intervals in the short direction of the rubber sheet W placed on the table 20 (the left-right direction in Fig. 10). The clamp bars 33 are square bars that sandwich the rubber plate W between them and the stoppers 32, extend parallel to the stoppers 32, and in the example of Fig. 10, three rows are provided so as to form pairs with each stopper 32. The height of the upper surface of the clamp bars 33 is approximately the same as the height of the upper surface (main surface) of the rubber plate W that rests on the base plate 21 via the bed 22. In the example of Fig. 10, the upper surface of the stoppers 32 is slightly lower than the upper surface of the clamp bars 33, but it may be approximately the same height.

[0026] These clamp bars 33 are connected to connecting members 36 via clamp bar stoppers 35. As described above, each clamp bar stopper 35 passes through a slit in the base plate 21 and connects the clamp bar 33, which protrudes above the base plate 21, to a connecting member 36 located below the base plate 21 and inside the frame 31. A plurality of connecting members 36 are arranged at intervals in the extension direction of the stopper 32, and multiple connecting members 36 (two in the example in FIG. 9) are connected to each other by a counter base 37, which is a rod-shaped connecting member. The counter base 37 is connected to the frame 31 via an air cylinder 34 and moves left and right in FIG. 10 as the air cylinder 34 expands and contracts. As a result, the clamp bar 33 advances and retreats in the width direction of the rubber sheet W relative to the stopper 32, causing the side of the rubber sheet W to be clamped (clamped) or released (unclamped) by the clamp mechanism 30.

[0027] In this way, the stopper 32 and the clamp bar 33 constitute the clamp of the clamp mechanism 30, and clamp the rubber plate W by contacting only both side surfaces facing the width direction (left and right direction in FIG. 10) of the rubber plate W. In this embodiment, the opposing surfaces of the stopper 32 and the clamp bar 33, i.e., the opposing portions of the stopper 32 and the clamp bar 33 with respect to the rubber plate W set on the table 20, are flat. In this embodiment, the stopper 32 and the clamp bar 33 are configured so as not to overlap the top surface of the rubber plate W in a plan view when clamping the rubber plate W, i.e., so as not to hide even a part of the top surface of the rubber plate W in a plan view.

[0028] -Drill mechanism- The drill mechanism 40 includes a body 42 and a head 43. The body 42 is movable horizontally relative to the table 20 in parallel with the stopper 32, the rubber plate W, etc. (left-right direction in FIG. 7), and is also movable in a direction perpendicular to the stopper 32 (up-down direction in FIG. 7). The body 42 also supports the head 43 so that it can move up and down (up-down direction in FIG. 6). That is, the head 43 moves translationally in three dimensions. The head 43 has a drill 41 attached to a spindle, which rotates the drill 41. The horizontal position of the drill 41 is adjusted to the desired coordinates, and the drill 41 is rotated to lower the head 43, thereby drilling a bolt hole in the rubber plate W set on the table 20.

[0029] Here, the cushion rubber manufacturing apparatus 10 of this embodiment is a type of machining center, and the head 43 is equipped with an ATC (Automatic Tool Changer) 44. The drill 41 has a shank, and is attached to the main spindle of the head 43 via the shank by the ATC 44. When cutting the rubber sheet W, the drill 41 is replaced with a cutter (circular saw) 45 by the ATC 44. FIG. 5 shows a state in which the cutter 45 is attached to the head 43. The cutter 45 is attached to the head 43 in an orientation perpendicular to the longitudinal direction of the rubber sheet W, and cuts the rubber sheet W to a desired length. Chips generated during processing by the drill 41 and cutter 45 are received in a chip receiver 14 (FIG. 5).

[0030] -Press mechanism- 11, the pressing mechanism 50 includes a rail 51 that extends vertically and is attached to the head 43, a lifting mechanism 52 that moves along the rail 51, a slide mechanism 53 that is connected to the bottom of the lifting mechanism 52, and a presser foot 54 that is attached to the slide mechanism 53. The slide mechanism 53 is configured using, for example, an air cylinder. The presser foot 54 moves vertically (in the drilling direction of the drill 41) as the lifting mechanism 52 moves, and moves horizontally (in the longitudinal direction of the rubber plate W set on the table 20 in this embodiment) as the slide mechanism 53 expands and contracts.

[0031] The presser fitting 54 is configured to hold the rubber sheet W around the drill 41. In this embodiment, the presser fitting 54 is formed in a ring shape having a hole 55 through which the drill 41 passes, and holds the rubber sheet W so as to surround the periphery of the drill 41. That is, when drilling a hole in the rubber sheet W, the presser fitting 54 holds the top surface of the rubber sheet W with the hole 55 aligned with the drilling position. The drill 41 then passes through the hole 55 of the presser fitting 54 that is holding the rubber sheet W and cuts into the rubber sheet W. Note that, in this embodiment, the presser fitting 54 is configured to hold the rubber sheet W so as to surround the entire periphery of the drill 41, but it may also be configured to hold the rubber sheet W at at least one location near the drill 41 (for example, a position at a distance from the drill 41 that is equal to or less than the drill diameter) instead of holding the rubber sheet W so as to surround the entire periphery.

[0032] The presser fitting 54 is retracted to a predetermined storage position when not in use, for example, when cutting the rubber sheet W with the cutter 45. For example, a state in which the lifting mechanism 52 is raised to a predetermined height and the slide mechanism 53 is fully contracted can be exemplified as a state in which the presser fitting 54 is retracted to the predetermined storage position.

[0033] -Control device- The control device 60 includes a processing device such as a CPU and a computer having storage devices such as RAM and ROM, and has the function of controlling (e.g., NC control) the drill mechanism 40 and the press mechanism 50 so that the drill 41 drills holes in the rubber sheet W while the rubber sheet W is held down by the presser fittings 54, as described above. When drilling holes in the rubber sheet W, the control device 60 executes at least some of the movements of the rubber sheet W approaching the drill mechanism 40 and the presser fitting 50 in parallel, in accordance with input data such as the pitch and diameter of the bolt holes and the tools used. For example, the control device 60 first lowers the head 43 with the presser fitting 54 positioned immediately below the drill 41 (the holes 55 of the drill 41 and the presser fitting 54 are aligned coaxially above and below), and then moves the presser fitting 54 and the drill 41 toward the rubber sheet W together. Thereafter, once the preceding presser fitting 54 has held down the rubber sheet W, the control device 60 moves the lifting mechanism 52 relative to the head 43 (upward) to maintain the position of the presser fitting 54, and lowers the head 43. As a result, the rubber plate W is drilled with the drill 41 while the rubber plate W is held down by the metal press 54 .

[0034] The control device 60 also has a function of controlling the drill mechanism 40 and the pressing mechanism 50 so that, after drilling a hole in the rubber plate W, the drill 41 is removed from the rubber plate W with the pressing mechanism 50 holding the rubber plate W. That is, after drilling a hole in the rubber plate W, the control device 60 moves the lifting mechanism 52 relative to the head 43 (downward) to raise the head 43 while maintaining the position of the presser fitting 54. As a result, the drill 41 is removed from the rubber plate W with the presser fitting 54 holding the rubber plate W.

[0035] The control device 60 also has a function of replacing the drill 41 with a cutter 45 after drilling the rubber plate W, cutting the rubber plate W to a desired length, and forming it into the shape of the cushion rubber CR.

[0036] 5, the cushion gum manufacturing apparatus 10 is equipped with an operation switch 61. The operation switch 61 is equipped with a start button, a pause button, a stopper button, an emergency stop button, etc. For example, the operator can use the start button or the pause button to instruct the start or stop of the series of processing operations described above, prohibit operations with the stopper button, or urgently stop the operation of the cushion gum manufacturing apparatus 10 with the emergency stop button.

[0037] The operations of the drill mechanism 40, the pressing mechanism 50, etc. do not necessarily have to be controlled by the control device 60. The cushion rubber for the loading platform lifting device can also be manufactured by a manual manufacturing method. In this case, the operator first opens the shutter 13 and places the long rubber plate W on the table 20, and clamps the rubber plate W placed on the table 20 from its width direction with the clamp mechanism 30. Next, the operator closes the shutter 13 and manually operates the drill mechanism 40 and the pressing mechanism 50, and drills holes in the rubber plate W with the drill mechanism 40 while pressing the rubber plate W held by the clamp mechanism 30 against the table with the pressing mechanism 50.

[0038] -effect- (1) Before being processed by the cushion rubber manufacturing apparatus 10, the rubber sheet W may be stored in a rolled state. The rolled rubber sheet W is expanded during processing, but it often becomes wavy when drilled. For example, if drilling is performed while the sheet is simply held down in the width direction by the clamping mechanism 30, variations in the precision of the positions and shapes of the drilled bolt holes may occur.

[0039] In contrast, in this embodiment, the pressing mechanism 50 presses the rubber plate W in the drilling direction against the table 20, thereby keeping the rubber plate W flat during processing. This makes it possible to drill bolt holes of the desired shape in the rubber plate W with high positional accuracy when manufacturing cushion rubber CR for a loading platform lifting device.

[0040] (2) Figure 12 is a schematic diagram of a clamping mechanism according to a comparative example. During the development process of a cushion rubber manufacturing device, a general aluminum processing machine was used to create a configuration in which the rubber sheet W was held by only the pressing force acting on the side of the sheet during drilling. However, it was found that the rubber sheet W, which is undulating unlike metal materials, would get caught on the drill as it rose after drilling, causing it to lift up and come off the clamp. Therefore, as shown in Figure 12, the metal fitting X that comes into contact with the rubber sheet W of the clamp was made in an inverted L shape, and a barb was provided on the top of the metal fitting X, which prevented the rubber sheet W from lifting up.

[0041] However, with the configuration shown in Figure 12, the barbs on the metal fittings X get in the way, making it difficult and time-consuming to set and remove the rubber sheet W from the cushion rubber manufacturing device. There was also concern that the barbs on the metal fittings X would become an obstacle when drilling holes in the edge of the rubber sheet W, affecting the design freedom of the cushion rubber CR.

[0042] Therefore, in the cushion rubber manufacturing apparatus 10 of this embodiment, the clamps of the clamping mechanism 30 are configured to contact only both sides of the rubber plate W facing the width direction, thereby leaving the top surface of the rubber plate W widely open, while the pressing mechanism 50, which descends together with the drill 41, suppresses lifting of the rubber plate W separately from the clamping mechanism 30. This makes it possible to expose the entire top surface of the rubber plate W while suppressing lifting of the rubber plate W during and after drilling, thereby increasing the degree of freedom in the drilling position relative to the rubber plate W, in other words, the degree of freedom in the design of the cushion rubber CR.

[0043] (3) Furthermore, the pressing mechanism 50 presses the rubber plate W around the drill 41. In particular, in this embodiment, the pressing metal fitting 54 is formed in a ring shape having a hole 55 through which the drill 41 passes, so that the rubber plate W is pressed so as to surround the entire periphery of the drill 41. This allows the rubber plate W to be pressed close to the drill 41 while drilling, which is more advantageous in ensuring the accuracy of the position and shape of the bolt holes in the cushion rubber CR.

[0044] 12, when the metal fitting X of the clamp is used to prevent the rubber plate W from floating up, the distance between the metal fitting X and the drilling position varies depending on the design of the cushion rubber CR and the bolt holes, which can cause variations in how effectively the rubber plate W is held down. In contrast, in this embodiment, the positional relationship between the position where the pressing mechanism 50 presses the rubber plate W and the drilling position can be maintained, and variations in how effectively the rubber plate W is held down can also be reduced.

[0045] (4) Furthermore, the control device 60 has a function for controlling the drill mechanism 40 and the pressing mechanism 50 so that the drill 41 is removed from the rubber plate W while the pressing mechanism 50 holds the rubber plate W after drilling, thereby automatically preventing the rubber plate W from coming off the clamp. This prevents the need for re-setting the rubber plate W and allows continuous or efficient drilling of the rubber plate W.

[0046] (5) Furthermore, by providing the control device 60 with a function to execute the approaching operation (lowering operation) of the drill mechanism 40 and the pressing mechanism 50 toward the rubber plate W at least partially in parallel when drilling holes in the rubber plate W, the processing time of the rubber plate W and, ultimately, the manufacturing time of the cushion rubber CR can be shortened to the extent that the approaching operations of the drill mechanism 40 and the pressing mechanism 50 toward the rubber plate W overlap in time.

[0047] -Variations- In the above embodiment, an example has been described in which the cushion rubber manufacturing apparatus 10 is used to manufacture cushion rubber CR for use in a loading platform lifting device 100 in which the loading platform 4 assumes an upright position when stored. However, it goes without saying that the cushion rubber manufacturing apparatus 10 can also be applied to manufacturing cushion rubber for use in other types of loading platform lifting devices. Loading platform lifting devices include, for example, a type in which the loading platform is retracted and stored under the chassis frame. Furthermore, even among loading platform lifting devices in which the loading platform is stored upright, there are types in which the loading platform 4 is raised and lowered by the pivotal movement of an arm, rather than the type in which the loading platform 4 is raised and lowered along vertical posts 1L, 1R as in the above embodiment. Cushion rubber for use in the loading platforms of these different types of loading platform lifting devices can also be manufactured using the cushion rubber manufacturing apparatus 10. [Explanation of symbols]

[0048] 10... cushion rubber manufacturing device, 20... table, 30... clamp mechanism, 32... stopper (clamp), 33... clamp bar (clamp), 40... drill mechanism, 41... drill, 50... pressing mechanism, 54... holding metal fitting, 60... control device, 100... load receiving platform lifting device, CR... cushion rubber, W... rubber plate

Claims

1. A manufacturing device for cushion rubber for a loading platform lifting device, a table on which a long rubber plate is placed; a clamping mechanism that clamps the rubber plate placed on the table in a width direction of the rubber plate; a drill mechanism that drills holes in the rubber plate clamped by the clamp mechanism; a pressing mechanism that presses the rubber plate clamped by the clamp mechanism in the drilling direction of the drill and presses it against the table; 1. A manufacturing device for cushion rubber for a load-receiving platform lifting device, comprising:

2. 2. The manufacturing apparatus for cushion rubber for a loading platform lifting device according to claim 1, The clamping mechanism has clamps that contact only both sides of the rubber plate facing in the width direction, and the rubber plate is clamped by these clamps.

3. 3. The manufacturing apparatus for cushion rubber for a loading platform lifting device according to claim 2, 10. A manufacturing device for cushion rubber for a loading platform lifting device, wherein the portion of the clamp facing the rubber plate is flat.

4. 2. The manufacturing apparatus for cushion rubber for a loading platform lifting device according to claim 1, The manufacturing device for cushion rubber for a load-receiving platform lifting device is characterized in that the pressing mechanism is provided with a pressing metal fitting that presses the rubber plate around the drill.

5. 5. The manufacturing apparatus for cushion rubber for a loading platform lifting device according to claim 4, The manufacturing device for cushion rubber for a loading platform lifting device is characterized in that the clamp is formed in a ring shape having a hole through which the drill is passed.

6. In the manufacturing apparatus for cushion rubber for a load-receiving platform lifting device according to any one of claims 1 to 5, a control device for controlling the clamping mechanism, the drilling mechanism, and the pressing mechanism; The manufacturing device for cushion rubber for a loading platform lifting device is characterized in that the control device controls the drill mechanism and the pressing mechanism so that the drill drills a hole in the rubber plate while holding down the rubber plate.

7. 7. The manufacturing apparatus for cushion rubber for a loading platform lifting device according to claim 6, The control device is characterized in that after drilling a hole in the rubber plate, it controls the drill mechanism and the pressing mechanism so that the drill is removed from the rubber plate while the pressing mechanism holds the rubber plate down.

8. The manufacturing apparatus according to claim 7, The manufacturing device for cushion rubber for a loading platform lifting device is characterized in that, when drilling holes in the rubber plate, the control device performs at least some of the approaching operations of the drill mechanism and the pressing mechanism toward the rubber plate in parallel.

9. A method for manufacturing a cushion rubber for a loading platform lifting device, comprising: Place a long rubber plate on the table, The rubber plate placed on the table is clamped by a clamp mechanism from the width direction of the rubber plate, The rubber plate clamped by the clamping mechanism is pressed against the table by a pressing mechanism, and holes are drilled in the rubber plate by a drilling mechanism. A method for manufacturing a cushion rubber for a load-receiving platform lifting device, comprising:

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