JP2006088946A - Lifting/lowering device of storage type load receiving platform - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an lifting/lowering device for an storage type load receiving platform capable of preventing the load receiving platform etc. from being damaged by prohibiting the rise and fall of the platform in compliance with the manipulation of the operation part inside a load carrying platform while the load receiving platform is in the condition of not being spread sufficiently. <P>SOLUTION: The lifting/lowering device 4 is for the storage type load receiving platform and structured as capable of being accommodated under the load carrying platform of a vehicle 3, wherein the load receiving platform 5 has a base end 23 and a body 25 to be folded up upon rotating to over the base end 23 from the spread condition, and the lifting/lowering device 4 is equipped with the operation part 35 installed inside the load carrying platform for manipulating the lifting and lowering motions of the load receiving platform 5, a proximity switch 32 to sense whether the load receiving platform 5 is in the spread condition, and a control circuit device 53 to emit a drive command signal for lifting and lowering the load receiving platform 5 in compliance with the manipulation of the operation part 35 only when the proximity switch 32 has sensed the spread condition of the load receiving platform 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a retractable cradle lifting device that can be stored on the lower side of a pallet of a vehicle.

  The load receiving platform lifting / lowering device lifts and lowers the load receiving platform between the height of the loading platform floor of the vehicle and the height of the ground to support loading and unloading operations on the loading platform of the vehicle. There are various types of such load receiving table lifting devices, and an example thereof is a retractable load receiving device lifting device that can be stored on the lower side of the vehicle. As a prior art of this retractable cargo receiving platform lifting apparatus, for example, a slide rail fixed to the lower part of the vehicle, and a slider (first support plate, sliding member, etc.) that can slide in the longitudinal direction of the vehicle along this slide rail A parallel link (upper arm and lower arm) that pivots up and down with the slider as a base, a load receiving base that is connected to the distal end side of the parallel link and that can be folded, and a load receiving base on the arm constituting the parallel link The structure provided with the detection switch which operate | moves when Fold is folded, and the loading platform outer side operation part (switch box) which has a key switch and a raising / lowering switch (toggle switch) is disclosed (for example, refer patent document 1 etc.).

  In this retractable load receiving device, for example, when shifting from the retracted state to the working state, when the operator holds the key switch in the “ST” position, the folded load receiving stand is slid out of the vehicle and then pulled out. When the operator operates the elevating switch to the “down” position, the load receiving table descends (rotates) while being in contact with the guide roller via the parallel link, and is slightly upright. Then, when the operator unfolds the folded load receiving platform and operates the lift switch to the “up” or “down” position, the load receiving table is raised and lowered between the ground and the loading platform. On the other hand, when shifting from the working state to the retracted state, for example, when the operator folds the load receiving table and leans against the guide roller and operates the lift switch to the “up” position, the load receiving table rolls against the guide roller via the parallel link. It rises (rotates) and becomes approximately horizontal. At this time, the detection switch is activated and automatically switched. When the operator continues to operate the lift switch to the “up” position, the load receiving table is slid forward and stored. Since the series of operations as described above are performed by a loading platform outer side operation unit provided in the vicinity of the loading platform elevating device, the operator performs it while visually checking the loading platform and the surroundings.

  As another example, there is a load receiving platform lifting device having an opening / closing mechanism that is normally in a closed state in which the load receiving stand stands along the rear surface of the load box and is rotated to an open state in which the load receiving stand is laid down approximately horizontally. Are known. This cargo bed lifting / lowering device is provided, for example, outside the cargo bed, and includes a cargo bed outer side operation unit having an open / close switch, a lift switch, and a lowering switch, and a cargo bed inner side operation unit provided inside the cargo box and having the lift switch and the lowering switch. (For example, refer patent document 2).

  In this loading platform lifting device, when the opening / closing switch and the lifting switch of the loading platform outer operation unit are operated simultaneously, the loading platform is turned to the closed state, and when the opening / closing switch and the lowering switch of the loading platform outer operation unit are operated simultaneously, Is rotated to an open state. Further, when the lifting switch of the loading platform outer operation unit is operated alone, the loading platform is raised, and when the lowering switch of the loading platform outer operation unit is operated alone, the loading platform is lowered. And even if the raising switch or the lowering switch of the inside operation part of the loading platform is operated, the loading platform can be raised and lowered. As a result, workability in loading / unloading work inside the loading platform is improved.

JP 2000-108765 A JP 2001-63443 A

However, the following problems exist in the above-described conventional technology.
That is, it is assumed that the retractable load receiving device elevating device is provided with an inner operation portion that is provided inside the load carrier and has an elevating switch. In this case, it becomes possible to perform the lifting / lowering operation and the storing operation of the loading platform described above by operating the lifting switch of the inside operation unit of the loading platform, and the workability is improved. However, the operator who operates the operation part inside the loading platform may not be able to visually check the loading platform, and there is a possibility that the loading platform is moved up and down without confirming whether or not the loading platform is fully deployed. . Then, if the load receiving platform is not fully deployed, or if the load receiving platform is slightly folded during operation, the moving load receiving platform may collide with the loading platform and be damaged. Also, when storing the cargo cradle by operating the lift switch on the inside operation part of the cargo bed, if the operator cannot see it and slides in front of the vehicle with the cargo cradle not fully folded, Etc. may be damaged.

  A first object of the present invention is a retractable cradle that can prevent the cradle from being lifted and lowered in a state where the cradle is not sufficiently unfolded in accordance with the operation of the operation unit on the inner side of the cradle, and can prevent damage to the cradle. The object is to provide a lifting device.

  The second object of the present invention is to reliably prohibit the receiving platform from being retracted in accordance with the operation of the operation unit on the inner side of the loading platform, and to prevent the receiving platform from being slid and damaged without being fully folded. An object of the present invention is to provide a retractable cargo receiving platform lifting device.

  (1) In order to achieve the above object, the present invention relates to a retractable load receiving device lifting device that can be stored below a load carrier of a vehicle. A load receiving platform having a load receiving platform main body that is pivoted upward and folded, a loading platform inner operation section that is provided inside the vehicle loading platform and that can operate the lifting operation of the load receiving platform, and the load receiving platform is in an unfolded state. An unfolding state detecting means for detecting whether or not there is, and an elevating control means for raising and lowering the load receiving base only when the unfolding state detecting means detects the unfolding state of the load receiving base with respect to the operation of the inside operation unit of the loading platform. Is provided.

  In the present invention, whether or not the cargo cradle is in the unfolded state is detected by the unfolded state detecting means. To do. Accordingly, it is possible to prevent the load receiving platform from being lifted and lowered in a state where the load receiving platform is not sufficiently deployed in accordance with the operation of the operation unit on the inside of the loading platform, and to prevent the cargo receiving platform being lifted from colliding with the loading platform or the like from being damaged. . In addition, since the inside operation part of the loading platform can be operated only for the lifting and lowering operation of the loading platform, for example, the slide drive unit that slides the loading platform to store and withdraw the loading platform, and the sliding operation of the loading platform can be operated. Even when such an operating means is provided, the sliding operation of the load receiving platform cannot be operated at the operation portion inside the loading platform. In addition, as described above, the lifting operation of the folded cargo cradle as preparation for storage cannot be operated by the cargo bed inner side operation unit. Accordingly, it is possible to reliably prohibit the receiving platform from being stored in accordance with the operation of the loading platform inner side operation unit, and it is possible to prevent the receiving platform from being slid and damaged without being sufficiently folded.

  (2) In order to achieve the above object, the present invention also relates to a retractable load receiving device elevating device that can be stored under a load receiving platform of a vehicle, in a deployed state with respect to the load receiving stand base end portion and the load receiving stand base end portion. A load receiving platform having a load receiving platform main body that is turned upward and folded, and a slide that slides the load receiving platform in order to store the load receiving platform below the loading platform of the vehicle or to pull it out of the vehicle. A drive unit, an elevating drive unit that elevates and lowers the load receiving platform via a parallel link, a load platform outer operation unit that is provided outside the vehicle load platform and is capable of operating a sliding operation and an elevating operation of the load receiving table; In response to the operation of the cargo bed inner side operation unit provided inside the cargo bed and capable of operating the lifting operation of the cargo bed, the unfolding state detecting means for detecting whether or not the cargo bed is in the unfolded state, and the operation of the cargo bed inner side operation unit , The deployment state detection Only when detecting the development state of the receiving platform in means, and a lift control means for lifting said receiving platform.

  (3) In the above (1) or (2), preferably, the unfolded state detecting means is a non-contact type proximity switch provided at the base of the cargo receiver.

  According to the present invention, in accordance with the operation of the cargo bed inner side operation part, it is prohibited to move up and down in a state where the cargo carrier is not sufficiently unfolded, and damage to the cargo carrier can be prevented. In addition, it is possible to reliably inhibit the load receiving table from being stored in accordance with the operation of the operation unit on the inner side of the loading platform, and to prevent the load receiving table from being slid and damaged without being fully folded.

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

  FIG. 1 is a side view showing the overall structure of a vehicle to which an embodiment of a cargo receiving platform lifting apparatus of the present invention is applied. In the following, when the vehicle is in the cab in the state shown in FIG. 1, the driver's front side (left side in FIG. 1), rear side (right side in FIG. 1), left side (on the paper surface in FIG. 1). The front side and the right side (back side toward the paper surface in FIG. 1) are simply referred to as the front side, the rear side, the left side, and the right side.

  In FIG. 1, this vehicle includes a cab 2 provided in front of a vehicle body (vehicle frame) 1, a cargo bed 3 provided on the vehicle body 1, and a cargo receiving platform lifting device 4 provided at a rear portion of the vehicle body 1. I have. This retractable load receiving platform lifting / lowering device 4 folds the load receiving stand 5 and stores it under the load receiving platform 3 during traveling operation, for example, and slides the load receiving stand 5 rearward during loading and unloading operations. 3 is raised and lowered between the floor height and the ground height.

  FIGS. 2 and 3 are perspective views showing the detailed structure of the retractable load receiving device elevating device 4. FIG. 2 shows a state in which the load receiving stand 5 is folded and stored, and FIG. It is a figure showing the state made. 4 and 5 are partially enlarged longitudinal sectional views showing a schematic structure around the base part of the load receiving base of the load receiving base 5. FIG. 4 shows a state in which the load receiving base 5 is folded. FIG. FIG.

  2 to 5, the retractable load receiving platform lifting / lowering device 4 is roughly divided into the load receiving platform (platform) 5 on which a load is loaded, and the rear portion of the vehicle body 1. 2 and a slide drive unit 6 that slides in the upper left and lower right directions in FIG. 3 and a lift drive unit 7 that lifts and lowers the load receiving platform 5 via a parallel link.

  The slide drive unit 6 includes a pair of left and right guide rails 8 extending in the front-rear direction at the rear portion of the vehicle body 1, and left and right sliders 9 that can be engaged and supported by the left and right guide rails 8 respectively. The connecting member 10 mounted on the left and right sliders 9, and the left and right bracket portions provided on the outside of the slider 9 in the connecting member 10 (lower left side and upper right side in FIGS. 2 and 3). 11 and left and right support frames 13 provided respectively on the rear side of the slider 9 (lower right side in FIG. 3) and provided with rollers 12 for supporting the load receiving platform 5 during storage and unfolding, The left and right slide cylinders 14 drive the right slider 9 respectively. The left / right slider 9, the connecting member 10, the left / right bracket portion 11, and the left / right support frame 13 are integrated into the left / right slide by driving the left / right slide cylinder 14 to extend and contract. It moves in the front-rear direction along the guide rail 8.

  Further, the left and right guide rails 8 are provided with stoppers 15 and 16 (see FIGS. 8 to 12 to be described later) for restricting the range of movement of the slider 9 in the front-rear direction, respectively. A work position sensor 17 (see FIG. 7 to be described later) is provided for detecting whether or not it is in a state of contact with 16 (hereinafter referred to as a work position). The support frame 13 is provided with a storage position sensor 18 for detecting whether or not the folded load receiving platform 5 is placed at a predetermined height and is slidable (hereinafter referred to as a storage position). .

  The elevating drive unit 7 includes a first arm (tilt arm) 19 whose upper end portion is rotatably connected to the bracket portion 11, and a front end portion rotatably connected to the first arm 19 and a rear end portion that is a load receiving platform. A second arm 20 rotatably connected to 5 and a third arm (compression arm) having a front end portion rotatably connected to the bracket portion 11 and a rear end portion rotatably connected to the cargo receiver 5. 21 and the rod side (upper left side in FIGS. 2 and 3) are rotatably connected to the lower end of the first arm 19, and the bottom side (lower right side in FIGS. 2 and 3) rotates to the second arm 20. The first arm 19, the second arm 20, the third arm 21, and the lift cylinder 22 are provided in a pair of left and right. And the 2nd arm 20 and the 3rd arm 21 form a parallel link, and this parallel link rotates to the up-down direction by the expansion-contraction drive of the lift cylinder 22, Thereby, the load receiving stand 5 raises / lowers.

  The load receiving platform 5 includes a load receiving platform base end 23 supported by the elevating drive unit 7, a load receiving base main body 25 rotatably connected to the load receiving platform base end 23 via a hinge 24, and the load receiving platform 5. It is comprised with the load receiving stand front-end | tip part 27 connected with the base main-body part 25 via the hinge 26 so that rotation was possible. Both ends of the hinge 24 are pivotally connected to the vicinity of the upper surfaces of the load receiving base end portion 23 and the load receiving base body portion 25 via pins 28 and 29, respectively, and the load receiving base main body portion 25 with respect to the load receiving base end portion 23. Is a double joint structure with a hinge 24 interposed therebetween. Similarly, both ends of the hinge 26 are pivotally connected to the vicinity of the upper surfaces of the load receiving table main body 25 and the load receiving table tip 27 via pins (not shown), respectively. The turning mechanism of the distal end portion 27 has a double joint structure through the hinge 26. And the load receiving base main-body part 25 and the load receiving stand front-end | tip part 27 rotate upwards from an unfolded state, and are folded.

  Further, the load receiving base end 23, the load receiving main body 25, and the load receiving front end 27 are respectively provided with stopper portions 30 that come into contact with each other when in the unfolded state. 23, the upper surface of the load receiving table main body 25 and the load receiving table tip 27 are continuous with each other to form a smooth surface.

  The hinge 24 is provided with a protruding dock 31, and the dock 31 is rotated via a pin 28. A non-contact type proximity switch 32 is provided in the vicinity of the hinge 24 of the load receiving base end portion 23. Then, as shown in FIG. 5, when the load receiving base body 25 is in the unfolded state with respect to the load receiving base end 23, the dock 31 comes close to the detection surface 32 a of the proximity switch 32, whereby the proximity switch 32 is unfolded. The state is to be detected.

  In addition, a hydraulic drive device (power unit) 33 for driving the slide cylinder 14 and the lift cylinder 22 and a load receiving table elevating device 4 are operated at the ends of the left and right bracket portions 11 of the slide drive portion 6. Possible cargo bed outer side operation parts (switch boxes) 34 are provided respectively. In addition, a loading platform inner side operation unit 35 (see FIG. 7 described later) capable of operating the loading platform lifting device 4 is provided inside the loading platform 3.

  FIG. 6 is a hydraulic circuit diagram illustrating a schematic configuration of the hydraulic drive device 33 as an example.

  In FIG. 6, the hydraulic drive device 33 includes an electric motor (prime mover) 36, a hydraulic pump 37 driven by the electric motor 36, an oil tank 38 provided on the suction side of the hydraulic pump 37, and a hydraulic pump 37. A pressure oil supply passage 39 for supplying pressure oil discharged from the lift cylinder 22, a first lift switching valve 40 capable of switching the flow of the pressure oil supply passage 39 to a communication / blocking state, and pressure oil supply A pressure oil return passage 41 that is branched downstream of the first lift switching valve 40 in the passage 39 and communicated with the oil tank 38, and a second that can switch the flow of the pressure oil return passage 41 to a communication / blocking state. A lift switching valve 42, a flow rate control valve 43 provided downstream of the second lift switching valve 42, and a relief valve 44 for defining the maximum value of the discharge pressure of the hydraulic pump 37; And a conductor relay 45 connected between the electric motor 36 and the battery (not shown).

  For example, when a drive command signal (electrical signal) is input to the conductor relay 45, the coil 45a is energized, and the contact 45b that is normally open is closed, and is electrically supplied from the battery via the contact 45b and is electrically driven. The motor 36 is driven, and thereby the hydraulic pump 37 is driven. At the same time, when a drive command signal is input to the solenoid portion 40a of the first lift switching valve 40, the first lift switching valve 40 is switched to the left communication position in FIG. At this time, since the second lift switching valve 42 is in the lower cutoff position in FIG. 6, the pressure oil discharged from the hydraulic pump 37 is supplied to the lift cylinder 22 via the pressure oil supply passage 39, and the lift cylinder 22. Is driven in the extending direction, and as a result, the receiving platform 5 is raised.

  On the other hand, for example, when a drive command signal is not input to the conductor relay 45, the contact 45b is opened and the electric motor 36 and the hydraulic pump 37 stop driving, and at the same time, the solenoid portion 42a of the second lift switching valve 42. When the drive command signal is input to the second lift switching valve 42, the second lift switching valve 42 is switched to the upper communication position in FIG. At this time, since the first lift switching valve 40 is in the cut-off position on the right side in FIG. 6, the pressure oil from the lift cylinder 22 flows into the oil tank 38 through the pressure oil return passage 41 by its own weight, and the lift cylinder 22 Driving in the contraction direction, as a result, the load receiving platform 5 is lowered.

  The hydraulic drive device 33 is branched on the upstream side of the first lift switching valve 40 in the pressure supply passage 39, and a pressure oil supply passage 46 for supplying pressure oil to the rod side of the slide cylinder 14; The pressure oil supply passage 46 is branched downstream of the throttle valve 47 and the check valve 48, and a pressure oil supply passage 49 for supplying pressure oil to the bottom side of the slide cylinder 14, and the pressure oil supply passage 49 A first slide switching valve 50 capable of switching the flow to a communication / blocking state, and a flow control valve 43 in the pressure oil return passage 41 that is branched downstream of the first slide switching valve 50 in the pressure oil supply passage 49. The pressure oil return passage 51 connected to the downstream side of the pressure oil and a second slide switching valve 52 capable of switching the flow of the pressure oil return passage 51 to a communication / blocking state.

  For example, when a drive command signal is input to the conductor relay 45, the electric motor 36 and the hydraulic pump 37 are driven as described above, and at the same time, the drive command signal is sent to the solenoid unit 50a of the first slide switching valve 50. Is input, the first slide switching valve 50 is switched to the upper communication position in FIG. At this time, since the second slide switching valve 52 is in the lower cutoff position in FIG. 6, the pressure oil discharged from the hydraulic pump 37 is supplied to the slide cylinder 14 via the pressure oil supply passage 49, and the slide cylinder 14. Is driven in the extending direction, and as a result, the load receiving platform 5 and the like slide backward.

  On the other hand, for example, when a drive command signal is input to the conductor relay 45, the electric motor 36 and the hydraulic pump 37 are driven, and at the same time, a drive command signal is input to the solenoid portion 52a of the second slide switching valve 52. The second slide switching valve 52 is switched to the upper communication position in FIG. At this time, since the first slide switching valve 50 is in the lower cutoff position in FIG. 6, the pressure oil discharged from the hydraulic pump 37 is supplied to the rod side of the slide cylinder 14 via the pressure oil supply passage 46. At the same time, the pressure oil from the bottom side of the slide cylinder 14 flows out to the oil tank 38 through the pressure oil return passage 51, and the slide cylinder 14 is driven in the contraction direction, so that the load receiving platform 5 and the like slide forward. It has become.

  When the load receiving platform 5 is raised, the first slide switching valve 50 is switched to the upper communication position in FIG. 6, the slide cylinder 14 is driven in the extending direction, and the slider 9 is moved to the rear stopper 16. You may make it press. Further, when the load receiving platform 5 is lowered, the first slide switching valve 50 may be switched to the upper communication position in FIG. 6 to communicate the rod side and the bottom side of the slide cylinder 14. Further, at the time of the rear slide of the above-described load receiving platform, the second slide switching valve 52 may be instantaneously switched to the upper communication position in FIG. 6 to depressurize the slide cylinder 14.

  FIG. 7 is an electric circuit diagram showing a configuration of a main part related to the drive control of the load receiving table elevating device 5.

  In FIG. 7, the loading platform outer side operation unit 34 provided outside the loading platform 3 and capable of operating the sliding operation and the lifting operation of the loading platform 5, and provided inside the loading platform 3 and capable of operating the lifting operation of the loading platform 5. The work position inner sensor 35, the work position sensor 17 for detecting whether or not the work receiving position 5 is at the work position pulled out rearward (see FIGS. 9 to 14 described later), and the folded load receiving position 5 are provided. The above-described storage position sensor 18 that detects whether or not the storage position is slidable (see FIGS. 8 and 9 to be described later) and whether or not the main body 25 of the load receiving base is in the unfolded state (see FIG. 11 to be described later). The proximity switch 32 and the control circuit device 53 are provided.

  The loading platform outer side operation unit 34 is, for example, of a pendant operation type having a push button type ascending switch 54A and a descending switch 54B, and an operation command signal corresponding to the operation of the ascending switch 54A or the descending switch 54B is transmitted through a cable or the like. Via the control circuit device 53.

  The control circuit device 53 is a control circuit composed of, for example, a plurality of relays or the like known as this type. First, as a first function, detection signals from the work position sensor 17 and the storage position sensor 18, the outside of the loading platform, An operation command signal from the operation unit 34 is input, and in response thereto, the conductor relay 45, the solenoid unit 40a of the first lift switching valve 40, the solenoid unit 42a of the second lift switching valve 42, and the above Drive command signals are output to the solenoid unit 50a of the first slide switching valve 50 and the solenoid unit 52a of the second slide switching valve 52, respectively.

  That is, for example, when the work position is not detected by the work position sensor 17 (in other words, when the load receiving platform 5 is stored, etc.), when the lowering switch 54B of the load platform outer side operation unit 34 is operated, the operation command signal In response to this, the drive command signal is output to the conductor relay 45 and the solenoid portion 50a of the first slide switching valve 50, respectively, and when the raising switch 54A is operated, the conductor relay 45 and the second relay command are output according to the operation command signal. A drive command signal is output to the solenoid part 52 a of the slide switching valve 52. Further, for example, when the work position is detected by the work position sensor 17 and the storage position is detected by the storage position sensor 18, if the raising switch 54 </ b> A of the loading platform outer side operation unit 34 is operated, the operation command signal is received. The drive command signal is output to the solenoid portion 52a of the conductor relay 45 and the second slide switching valve 52, and when the lowering switch 54B is operated, the drive command signal is sent to the solenoid portion 42a of the second lift switching valve 42. Is output. Further, for example, when the work position is detected by the work position sensor 17 and the storage position is not detected by the storage position sensor 18 (in other words, when the load receiving platform is unfolded or the like), the lift switch of the loading platform outer side operation unit 34 When 54A is operated, a drive command signal is output to the conductor relay 45 and the solenoid part 40a of the first lift switching valve 40 according to the operation command signal, and when the lowering switch 54B is operated, the second A drive command signal is output to the solenoid portion 42a of the lift switching valve 42.

  The cargo bed inner side operation unit 35 is of a pendant operation type provided with a push button type ascent switch 55A and a descent switch 55B, similar to the cargo bed outer side operation unit 34, for example, according to the operation of the ascending switch 55A or the descending switch 55B. An operation command signal is output to the control circuit device 53 via a cable or the like.

  Here, as a major feature of the present embodiment, as a second function, the control circuit device 53 inputs a detection signal from the proximity switch 32 and an operation command signal from the cargo bed inner side operation unit 35, and in response to these, Drive command signals are output to the conductor relay 45, the solenoid part 40a of the first lift switching valve 40, and the solenoid part 42a of the second lift switching valve 42, respectively.

  That is, for example, when the unfolded state of the cargo cradle body portion 25 is detected by the proximity switch 32, when the raising switch 55A of the cargo bed inner side operation portion 35 is operated, the conductor relay 45 and the first relay 45 are operated according to the operation command signal. A drive command signal is output to the solenoid unit 40a of the lift switching valve 40, and when the lowering switch 55B is operated, a drive command signal is output to the solenoid unit 42a of the second lift switching valve 42. Yes. On the other hand, for example, when the proximity switch 32 does not detect the unfolded state of the load receiving body 25, the output of the drive command signal is stopped.

  In the above description, the proximity switch 32 constitutes an unfolded state detecting means for detecting whether or not the load receiving table described in the claims is in the unfolded state. Only when the unfolded state of the load receiving table is detected by the unfolded state detecting means, the raising / lowering control means for raising and lowering the load receiving table is configured.

  Next, operations and effects of this embodiment will be described with reference to FIGS. In addition, in these FIGS. 8-14, illustration of the loading platform outer side operation part 34 is abbreviate | omitted for convenience.

(1) Transition from stored state to working state First, the case where the retractable load receiving table lifting device 4 is shifted from the stored state shown in FIG. 8 to the working state shown in FIG. 12 will be described. Initially, the folded load receiving platform 5 is stored below the loading platform 3, and a detection signal from the storage position sensor 18 is input to the control circuit device 53. When the operator inputs the lower switch 54 </ b> B of the loading platform outer side operation unit 34, the operation command signal is input to the control circuit device 53. The control circuit device 53 outputs a drive command signal to the conductor relay 45 and the solenoid unit 50a of the first slide switching valve 50 in response to the detection signal of the storage position sensor 18 and the operation command signal of the lowering switch 54B. Accordingly, the first slide switching valve 50 is switched to the communication position, and the pressure oil discharged from the hydraulic pump 37 is supplied to the slide cylinder 14. As a result, the slide cylinder 14 is driven in the extending direction, and the load receiving platform 5 and the like slide backward (right side in the figure).

  Then, as shown in FIG. 9, when the load receiving platform 5 is pulled out to the work position (the state where the slider 9 is in contact with the rear stopper 16), a detection signal from the work position sensor 17 is input to the control circuit device 53. The The control circuit device 53 outputs a drive command signal to the solenoid part 42a of the second lift switching valve 42 in response to the detection signal of the work position sensor 17 and the operation command signal of the lowering switch 54B. As a result, the second lift switching valve 42 is switched to the communication position, and the pressure oil from the lift cylinder 22 flows out to the oil tank 38 by its own weight. As a result, the lift cylinder 22 is driven in the contraction direction, the load receiving base end portion 23 is lowered via the parallel link, and the load receiving base base portion 25 and the load receiving stand distal end portion 27 are in contact with the roller 12 while being in contact with the roller 12. It rotates with respect to the end 23. Then, the load receiving base end portion 23 is grounded, and the load receiving base main body portion 25 and the load receiving tip front end portion 27 are slightly raised (see FIG. 10).

  And an operator expand | deploys the receiving stand 5 of the folded state. First, a grip (not shown) provided on the cargo cradle body 25 is pulled, and the cargo cradle body 25 is developed in a substantially horizontal state as shown in FIG. At this time, a detection signal from the proximity switch 32 is input to the control circuit device 53. Subsequently, a grip (not shown) provided at the front end portion 27 of the cargo cradle is pulled, and the front end portion 27 of the cargo cradle 27 is developed in a substantially horizontal state as shown in FIG.

(2) Working State Next, the working state shown in FIGS. 12 to 14 of the retractable load receiving table lifting device 4 will be described. For example, when the operator operates the lowering switch 54 </ b> B of the loading platform outer side operation unit 34 while visually confirming the unfolded state of the loading platform 5, the operation command signal is input to the control circuit device 53. In this case, the control circuit device 53 outputs a drive command signal to the solenoid part 42a of the second lift switching valve 42 in response to the detection signal of the work position sensor 17 and the operation command signal of the lowering switch 54B. For example, when the operator operates the lowering switch 55 </ b> B of the cargo bed inner side operation unit 35, the operation command signal is input to the control circuit device 53. In this case, the control circuit device 53 outputs a drive command signal to the solenoid part 42a of the second lift switching valve 42 in response to the detection signal of the proximity switch 32 and the operation command signal of the lowering switch 55B. As a result, as described above, the lift cylinder 22 is driven in the contraction direction, and the load receiving platform 5 is lowered via the parallel link. At this time, as shown in FIG. 12, in a state where the load receiving base end portion 23 is grounded, the first arm 19 is pulled by the lift cylinder 22 and rotates, and the entire load receiving stand 5 is inclined downward, The front end side of the load receiving table front end portion 27 is brought close to the ground (see FIG. 13). Thereby, it becomes easy to load a cart etc. on the cargo receiving stand 5, for example.

  For example, when the operator operates the raising switch 54 </ b> A of the loading platform outer side operation unit 34 while visually confirming the unfolded state of the loading platform 5, the operation command signal is input to the control circuit device 53. In this case, the control circuit device 53 does not receive the detection signal of the storage position sensor 18 and drives the conductor relay 45 and the solenoid portion 40a of the first lift switching valve 40 according to the operation command signal of the ascent switch 54A. Each command signal is output. For example, when the operator operates the raising switch 55 </ b> A of the cargo bed inner side operation unit 35, the operation command signal is input to the control circuit device 53. In this case, the control circuit device 53 outputs a drive command signal to the conductor relay 45 and the solenoid unit 40a of the first lift switching valve 40 in response to the detection signal of the proximity switch 32 and the operation command signal of the ascent switch 55A. To do. As a result, the first lift switching valve 40 is switched to the communication position, and the pressure oil discharged from the hydraulic pump 37 is supplied to the lift cylinder 22. As a result, the lift cylinder 22 is driven in the extending direction, and the load receiving platform 5 is raised. At this time, through the state shown in FIG. 12, the load receiving platform 5 can be raised to the floor surface height of the vehicle loading platform 3 as shown in FIG. Then, by repeatedly performing the operations shown in FIGS. 12 to 14, the burden of loading and unloading work on the loading platform 3 by the worker is reduced.

(3) Transition from Work State to Storage State Next, a case where the retractable load receiving table lifting device 4 is shifted from the work state shown in FIG. 12 to the storage state shown in FIG. 8 will be described. First, the operator folds the unloading stage 5 in the reverse order of the above-described procedures of FIGS. 10 to 12, and causes the load receiving body 25 and the load receiving end 27 to roll-contact with the roller 12. At this time, the detection signal from the proximity switch 32 is turned OFF. For example, when the operator operates the raising switch 54 </ b> A of the loading platform outer side operation unit 34 while visually confirming the folded state of the loading platform 5, the operation command signal is input to the control circuit device 53. The control circuit device 53 outputs a drive command signal to the conductor relay 45 and the solenoid unit 40a of the first lift switching valve 40 in response to the detection signal of the work position sensor 17 and the operation command signal of the ascent switch 54A. As a result, as described above, the lift cylinder 22 is driven in the extending direction, the load receiving platform 5 is raised via the parallel link, and the load receiving platform main body 25 and the load receiving platform distal end 27 are in contact with the roller 12 while receiving the load. It rotates with respect to the base end portion 23.

  Then, as shown in FIG. 9, when the entire receiving platform 5 is in a substantially horizontal state, a detection signal from the storage position sensor 18 is input to the control circuit device 53. The control circuit device 53 outputs a drive command signal to the conductor relay 45 and the solenoid portion 52a of the second slide switching valve 52 in response to the detection signal of the storage position sensor 18 and the operation command signal of the ascent switch 54A. As a result, the second slide switching valve 52 is switched to the communication position, the pressure oil discharged from the hydraulic pump 37 is supplied to the rod side of the slide cylinder 14, and the pressure oil from the bottom side of the slide cylinder 14 is also supplied. It flows out to the oil tank 38. As a result, the slide cylinder 14 is driven in the contraction direction, and the load receiving platform 5 slides forward (left side in the figure). Thereby, the cargo receiving platform 5 is stored on the lower side of the loading platform.

  As described above, in this embodiment, when the operator operates the loading platform outer side operation unit 34, the sliding operation and the lifting operation of the loading platform 5 are performed while visually confirming the loading platform 5 and its surroundings. Can do. On the other hand, when the operator operates the cargo bed inner side operation unit 35, the proximity switch 32 detects whether or not the cargo bed 5 is in the deployed state, and only when the cargo bed 5 is in the deployed state, the cargo bed inner side operation unit 35. In response to the operation, the cargo receiving platform 5 is raised and lowered. As a result, in accordance with the operation of the loading platform inner side operation unit 35, the loading platform 5 is prohibited from ascending and descending in a state where the loading platform 5 is not sufficiently deployed, and the loading platform 5 being lifted is prevented from colliding with the loading platform 3 and being damaged. can do.

  Moreover, since the loading platform inner side operation part 35 is set as the structure which can operate only the raising / lowering operation | movement of the loading platform 5, the sliding operation of the loading platform 5 cannot be operated. Further, the lifting operation (see FIGS. 9 and 10) of the folded load receiving platform 5 as preparation for storage cannot be performed by the load bed inner side operation unit 35. Accordingly, it is possible to reliably inhibit the receiving platform 5 from being stored in accordance with the operation of the loading platform inner side operation unit 35, and to prevent the loading platform 5 from being slid and damaged without being sufficiently folded. .

1 is a side view showing an overall structure of a vehicle to which an embodiment of a retractable load receiving device lifting apparatus of the present invention is applied. It is a perspective view showing the whole structure of one Embodiment of the retractable load receiving device raising / lowering apparatus of this invention, and represents the state by which the load receiving stand was folded and stored. It is a perspective view showing the whole structure of one Embodiment of the retractable receiving platform raising / lowering apparatus of this invention, and represents the state by which the receiving platform was pulled out and expand | deployed. It is a partial expanded longitudinal cross-sectional view showing the detailed structure around the receiving stand base end part of the receiving stand which comprises one Embodiment of the retractable receiving stand raising / lowering apparatus of this invention, and represents the state by which the receiving stand was folded. It is a partial expanded longitudinal sectional view showing the detailed structure around the load receiver base end portion of the load receiver that constitutes an embodiment of the retractable load receiver lifting device of the present invention, and shows a state in which the load receiver is deployed. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a hydraulic circuit diagram illustrating, as an example, a schematic configuration of a hydraulic drive device that constitutes an embodiment of a cargo receiving platform lifting device of the present invention. It is an electric circuit diagram showing the principal part structure in connection with the drive control of one Embodiment of the retractable cargo receiver raising / lowering apparatus of this invention. It is a side view for demonstrating operation | movement of one Embodiment of the retractable load receiving stand raising / lowering apparatus of this invention. It is a side view for demonstrating operation | movement of one Embodiment of the retractable load receiving stand raising / lowering apparatus of this invention. It is a side view for demonstrating operation | movement of one Embodiment of the retractable load receiving stand raising / lowering apparatus of this invention. It is a side view for demonstrating operation | movement of one Embodiment of the retractable load receiving stand raising / lowering apparatus of this invention. It is a side view for demonstrating operation | movement of one Embodiment of the retractable load receiving stand raising / lowering apparatus of this invention. It is a side view for demonstrating operation | movement of one Embodiment of the retractable load receiving stand raising / lowering apparatus of this invention. It is a side view for demonstrating operation | movement of one Embodiment of the retractable load receiving stand raising / lowering apparatus of this invention.

Explanation of symbols

3 Loading platform 4 Retractable loading platform elevating device 5 Loading platform 6 Slide driving section 7 Elevating driving section 19 First arm 20 Second arm 21 Third arm 23 Loading platform base section 25 Loading platform body section 32 Proximity switch (deployment state detection) means)
34 Cargo bed outer side operation part 35 Cargo bed inner side operation part 53 Control circuit device (elevation control means)

Claims (3)

In the retractable load receiving and lifting device that can be stored under the loading platform of the vehicle,
A load receiving base having a load receiving base main body part that is pivoted upward and folded from the unfolded state with respect to the load receiving base base end, and
A cargo bed inner side operation unit provided inside the cargo bed of the vehicle and capable of operating a lifting operation of the load receiving table;
An unfolding state detecting means for detecting whether or not the receiving platform is unfolded;
A retractable load receiving table comprising an elevating control means for raising and lowering the load receiving platform only when the unfolding state detecting means detects the unfolded state of the load receiving stand in response to the operation of the inner operation section of the loading platform. lift device. In the retractable load receiving and lifting device that can be stored under the loading platform of the vehicle,
A load receiving base having a load receiving base main body part that is pivoted upward and folded from the unfolded state with respect to the load receiving base base end, and
A slide drive unit that slides the cargo cradle to store the cradle under the cargo cradle of the vehicle or pull it out of the vehicle;
An elevating drive unit that elevates and lowers the load receiving table via a parallel link;
A loading platform outer side operation unit provided outside the loading platform of the vehicle and capable of operating a sliding operation and a lifting operation of the loading platform;
A cargo bed inner side operation unit provided inside the cargo bed of the vehicle and capable of operating a lifting operation of the load receiving table;
An unfolding state detecting means for detecting whether or not the receiving platform is unfolded;
A retractable load receiving table comprising an elevating control means for raising and lowering the load receiving platform only when the unfolding state detecting means detects the unfolded state of the load receiving stand in response to the operation of the inner operation section of the loading platform. lift device. 3. The retractable load receiving apparatus according to claim 1, wherein the unfolded state detecting means is a non-contact proximity switch provided at a base end of the load receiving base. .

Images