JP2009035114A - Lift of load carrying platform awning - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lift of a load carrying platform awning capable of smoothly lifting the awning in a stabler state in simple constitution. <P>SOLUTION: A plurality of the lifts 20 are arranged between a floor 3 of a load carrying platform 2 and an awning pipe structural body 11 to hold the awning 40, a cylindrical nut holder 23 on an upper surface 23A of which an upper side screw shaft through hole 24a communicated to the inside of an awning leg 21 opens and on a lower surface 23D of which a lower side screw shaft through hole 24b opens is provided on a lower end of the tubular awing leg 21 connected to the awning pipe structural body 11, an upper part of a screw shaft 30 supported on the floor 3 free to rotate and reciprocally rotated by an electric motor 35 is inserted into the awning leg 21 through the lower side screw shaft through hole 24b and the upper side screw shaft through hole 24a of the nut holder 23, a screw hole 25a to screw to the screw shaft 30 is drilled on a central part and a nut 25 rotation of which is regulated as end part outer peripheries 25b, 25c make contact with an inner surface of the nut holder 23 is stored in the nut holder 23. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a lifting device for a loading platform hood, and more particularly to a lifting device that is disposed between a floor of a loading platform and a hood structure holding a hood to lift and lower the hood structure.

  A hood device is widely used for protecting a cargo loaded on a cargo truck from sunlight, wind and rain, and dust.

  The hood device provided in the loading platform of such a lorry generally has an arched hood structure that connects between the upper ends of both side walls fixed to both side edges of the loading platform, and the hood is supported by the hood structure. is doing.

  However, since the height of the hood is set to be constant regardless of the height and volume of the cargo loaded on the loading platform, for example, in a place where the ceiling of the delivery destination is low or a parking lot with a height restriction, the height There is a problem that a truck with a hood with a height exceeding the height cannot be loaded, and the cargo cannot be delivered to the target location. On the other hand, when the height of the cargo loaded on the loading platform is low, there is a concern that the height of the hood becomes higher than necessary and excessive air resistance is generated during traveling, which may affect traveling performance and fuel efficiency. The

  As countermeasures, various lifting devices that adjust the height of the hood according to the height and volume of the load have been proposed.

  For example, an elevating device disclosed in Patent Document 1 is a sliding body in which a plurality of vertical grooves are provided on a wall plate extending upward from each side wall provided on both sides of a cargo bed, and are slidably disposed in each vertical groove. A side plate for supporting the hood bone structure is attached to each of the wall plates, and a rotatable rotating screw shaft and a frame that is screwed to the rotating screw shaft are attached to each wall surface plate, and the lower portion of the rotating screw shaft is extended in the front-rear direction along each side wall. By connecting the vertical axis extending through the bevel gear and connecting one end of each vertical axis to the horizontal axis extending in the vehicle width direction via the bevel gear, an operating handle provided at the other end of the vertical axis The hood bone structure is moved up and down by a turning operation to change the height of the hood.

  In addition, as another lifting device for the loading platform hood, four lifting devices that can be expanded and contracted vertically are set up at four corners of a rectangular floor, and the hood bone structure that holds the hood is supported by the four lifting devices, It is also known to move up and down the hood bone structure by simultaneously expanding and contracting four lifting devices at the same speed. In this case, each lifting device has a cylindrical hood leg 101 in which the upper end is fixed to the hood frame structure and the nut 102 is disposed at the lower end, and the lower end is rotatable to the floor, as shown in the cross section of the main part in FIG. A screw shaft 103 supported at the upper end is inserted into the hood leg 101 and screwed into the nut 102, and an electric motor that drives the screw shaft 103 to rotate forward and backward, and is screwed by the screw shaft 103 and the nut 102 screwed together. A feed mechanism 104 is configured. The hood leg 101 is raised by the screw feed mechanism 104 by the forward rotation driving of the screw shaft 103 by the electric motor, and the hood supported by the hood bone structure is raised, while the hood leg is driven by the reverse rotation driving of the screw shaft 103 by the electric motor. 101 descends and the hood bone structure and the hood descend.

Japanese Utility Model Publication No. 6-68939

  According to the above-mentioned Patent Document 1, a rotating screw shaft that rotates through the bevel gear by rotating the other vertical axis via the bevel gear or the horizontal axis by rotating the handle provided at the end of the one vertical axis. The sliding bar can be moved up and down in the longitudinal groove through the frame body and the hood bone structure can be moved up and down.

  However, a side plate that supports the hood bone structure is slidably mounted in a plurality of longitudinal grooves formed on the wall surface plate, and has a rotating screw shaft and a frame that are screwed together, and each rotating screw shaft, Since the vertical axis extending in the front-rear direction and the horizontal axis extending in the vehicle width direction are interlocked via a bevel gear, the configuration is extremely complicated and large, and there is a concern about an increase in manufacturing cost and installation space. Moreover, it takes a lot of labor to raise and lower the hood bone structure and the hood by rotating the operation handle, which places a lot of burden on the operator.

  On the other hand, in the latter case, four lifting devices that can be expanded and contracted at the four corners of the floor, and the lifting device for the loading platform hood that moves the hood bone structure that holds the hood up and down, any of the four lifting devices can be used. Even if one of them has different expansion / contraction speeds, the hood bone structure and the hood leg are inclined and the hood leg 101 coupled to the hood bone structure is inclined and the axis of the hood leg 101 and the screw shaft 103 supported by the loading platform are inclined. A shift occurs in the axis. More specifically, a shift occurs between the axis of the nut 102 and the axis of the screw shaft 103 that are screwed together, and the screw feed resistance by the nut 102 and the screw shaft 103 is increased, so that the hood can be lifted and lowered smoothly. Be disturbed. On the other hand, it is extremely difficult to uniformly maintain the expansion / contraction speed of each lifting device on which various different loads act.

  Accordingly, an object of the present invention made in view of such a point is to provide a lifting device for a loading platform hood that can smoothly lift and lower the hood in a stable state with a simple configuration.

  The lifting device for the loading platform hood according to claim 1, which achieves the above object, includes a plurality of lifting devices for lifting the loading platform hood that are arranged between the floor of the loading platform and the hood structure that holds the hood, and lifts the hood structure. In the apparatus, a cylindrical hood leg having an upper end coupled to the hood bone structure and extending in the vertical direction, and a shaft hood leg coupled to the lower end of the hood leg and extending across the axis of the hood leg. A nut holder in which an upper screw shaft through hole communicating with the inside of the hood leg is opened on the upper surface and a lower screw shaft through hole facing the upper screw shaft through hole is formed on the lower surface; A screw shaft that is rotatably supported by the floor and extends in the vertical direction, and an upper portion passes through the lower screw shaft through hole and the upper screw shaft through hole of the nut holder and is inserted into the hood leg. A screw hole that is screwed into the nut shaft is formed in the central portion, and the nut holder A nut that is accommodated with a gap between the inner surface and whose end is in contact with the inner surface of the nut holder and whose rotation is restricted, and a screw shaft rotation driving means that drives the screw shaft to rotate forward and backward. It is characterized by that.

  According to the present invention, when the hood bone structure and the hood are raised or lowered, the hood bone structure is inclined, and even if a deviation occurs between the axis of the hood leg and the axis of the screw shaft, The nut screwed to the screw shaft moves relative to the nut holder arranged at the lower end of the leg, and the shaft center of the screw shaft and the shaft center of the nut are held coaxially. The hood legs connected to the nut holder can be moved up and down smoothly by screw feeding, and smooth ascending and descending can be obtained by moving the hood bone structure up and down smoothly. Also, variation in the lifting and lowering speed of the hood leg between the lifting devices is allowed, and the required accuracy of each lifting device and hood structure can be relaxed. Assembling and accuracy requirements of each part are alleviated, and it can be configured at low cost, and the manufacturing cost can be reduced.

  According to a second aspect of the present invention, in the lifting device for the loading platform hood according to the first aspect, the loading platform has a side wall extending upward from a side edge of the floor, and is disposed on the side wall so as to raise and lower the hood leg. A hood leg holder that guides and guides in the direction, a rising end stop switch that regulates the rising end position of the hood leg by contact with the nut holder that is arranged at the lower end of the hood leg holder, and is arranged on the floor And a descent end stop switch that regulates the descent end position of the hood leg by abutting the nut holder that is lowered.

  According to the present invention, the top end stop switch is disposed at the lower end of the bottom leg holder disposed on the side wall to guide and guide the top leg in the vertical direction, and the bottom end stop switch is disposed on the floor. The bone structure and the hood can be stopped and held at the rising end position or the falling end position.

  According to a third aspect of the present invention, in the cargo platform top lifting device of the first or second aspect, the outer periphery of the end of the nut is covered with an annular buffer member made of an elastic material.

  According to the present invention, since the buffer member is disposed on the outer periphery of each end of the nut, generation of abnormal noise due to direct contact between the nut and the nut holder is avoided. In addition, even if vibration occurs in the hood and the hood structure due to vibrations caused by running and wind pressure acting on the hood, it is screwed onto the screw shaft and a nut holder provided on the hood leg connected to the hood structure. Direct contact with the nut is avoided, generation of abnormal noise can be avoided, and resonance of the hood bone structure and the hood can be suppressed.

  According to the present invention, when the hood bone structure and the hood are raised or lowered, even if the hood bone structure is inclined and a displacement occurs between the axis of the hood leg and the axis of the screw shaft, The nut that is screwed onto the screw shaft moves with respect to the nut holder that is arranged at the lower end of the leg, and the shaft center of the screw shaft and the shaft center of the nut are held coaxially. Rises and falls. Also, variation in the lifting and lowering speed of the hood leg between the lifting devices is allowed, and the required accuracy of each lifting device and hood bone structure can be relaxed, and the hood device can be configured at low cost. The manufacturing cost can be expected to be reduced.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a lifting platform lifting device according to the present invention will be described with reference to FIGS.

  FIG. 1 is a rear perspective view of a lorry in which a hood device provided with a lifting device according to the present embodiment is provided on a cargo bed, FIG. 2 is an enlarged view of the cargo bed portion of FIG. 1, and FIG. 3 is II of FIG. 4 is a perspective view of the lifting device, FIG. 5 is an enlarged view of a portion A in FIG. 4, FIG. 6 is a view as seen from an arrow B in FIG. 4, FIG. 7 is an enlarged view of a portion C in FIG. 5 is a sectional view taken along line II-II in FIG. In FIGS. 2 and 3, the hood is omitted. In each figure, an arrow F indicates the vehicle body front direction, and OUT indicates the vehicle width direction outward.

  In FIG. 1, reference numeral 1 denotes a freight vehicle. A loading platform 2 of the freight vehicle 1 includes a rectangular floor 3, left and right side walls 4 that are erected along both side edges of the floor 3, and a floor 3. A front wall 5 is provided between the front edges of the left and right side walls 4 along the front edge, and the upper and rear sides are opened to form a box shape. A rear gate (not shown), that is, an opening / closing door, is provided at the rear as necessary.

  The hood device 10 that covers the space between the left and right side walls 4 of the loading platform 2 from above will be described. The hood device 10 includes a hood bone structure 11 and a lifting device 20 that lifts and lowers the hood bone structure 11, and has a hood 40 held by the hood bone structure 11.

  As shown in FIGS. 2 and 3, the hood bone structure 11 includes left and right side hood bone structures 12 that cover the outside of the side walls 4 of the loading platform 2, and a front hood bone structure 16 that covers the front wall 5. Further, it is configured in a U-shape with a lower portion opened by a roof portion hood bone structure 17 that is installed between the left and right side hood bone structures 12 and covers the space between the left and right side walls 4 from above.

  Each side hood bone structure 12 includes an upper longitudinal frame 13 and a lower longitudinal frame 14 that extend in the longitudinal direction of the vehicle body along the outer surface of the side wall 4, and an upper longitudinal frame 13 and a lower frame. The side longitudinal frame 14 is formed in a rectangular frame shape by the hood bones of the front side frame 15a, the intermediate side frame 15b, and the rear side frame 15c installed on the front end portion, the rear end portion, and the intermediate portion, respectively.

  The front hood bone structure 16 extends in the vehicle width direction along the outer surface of the front wall 5 and is spanned between the lower ends and the upper ends of the front side frames 15a of the left and right side hood bone structures 12. The upper frame 16a and the lower frame 16b are formed in a rectangular frame shape by the left and right front side frames 15a, upper frames 16a, and lower frames 16b.

  The roof top frame structure 17 is an arch-shaped front roof frame that extends in the vehicle width direction and is erected between the front end and the rear end of the left and right upper longitudinal frames 13 and curved downward at both ends. 18a and a rear roof frame 18b, and a plurality of arch-like shapes that are arranged at equal intervals between the front roof frame 18a and the rear roof frame 18b and are erected on the left and right upper longitudinal frames 13 and curved downward. For example, three middle roof frames 18c, 18d, 18e and a center that extends in the front-rear direction and connects the front roof frame 18a, the middle roof frames 18c, 18d, 18e, and the middle part of the rear roof frame 18b to each other. An arch shape and a rectangular frame shape in plan view are formed by the hood bones of the longitudinal frame 18f.

  The lifting device 20 has four corners of the rectangular floor 3, that is, a front end portion and a rear end portion of the right side portion, a front end portion of the left side portion and end portions of the rear end portion, and a right upper vertical passage corresponding to each end portion. The frame 13 is stretched between the front end portion 13a and the rear end portion 13b of the frame 13 and the front end portion 13a and the rear end portion 13b of the upper side longitudinal frame 13 on the left side.

  Each lifting device 20 has the same configuration, and the lifting device 20 disposed between the front end portion on the left side of the floor 3 and the front end portion 13a of the left upper longitudinal frame 13 will be mainly described with reference to the others. The description of the lifting device 20 will be omitted.

  The lifting device 20 has an upper end coupled to the front end portion 13 a of the upper longitudinal frame 13 and extends coaxially with the hood leg 21 and the hood leg 21, and a lower end is rotatably supported on the floor 3 via a thrust bearing 31. A supported screw shaft 30 and an electric motor 35 for driving the screw shaft 30 to rotate forward and reverse are provided.

  The hood leg 21 has a cylindrical shape having an axial center extending in the vertical direction along the inner surface of the side wall 4, and has an upper end coupled to the front end portion 13 a of the upper longitudinal frame 13 by a bracket 22 and a columnar shape at the lower end. A cylindrical nut holder 23 that accommodates and holds the nut 25 in a swingable manner is coupled.

  As shown in FIGS. 5, 7, and 8, the nut holder 23 is opposed to a rectangular flat upper surface 23A whose central portion is coupled to the lower end of the hood leg 21 and bent downward from both side edges of the upper surface 23A. The rectangular flat planar side surfaces 23B and 23C and the bottom surface 23D spanned between the lower edges of the side surfaces 23B and 23C have an axis that intersects the axial direction of the hood leg 21, and the inner surface of the side wall 4. Is formed in a rectangular cylindrical shape that extends in the longitudinal direction of the vehicle body and opens at both ends.

  An upper screw shaft through hole 24a communicating with the inside of the hood leg 21 is formed in the upper surface 23A of the nut holder 23, and a lower screw shaft through hole 24b facing the upper screw shaft through hole 24a is formed in the lower surface 23D. The upper screw shaft through hole 24a and the lower screw shaft through hole 24b have an inner diameter through which the screw shaft 30 can be inserted with a gap, and are coaxial with the axis of the hood leg 21 and have an upper surface 23A and a lower surface. Open to 23D.

  The nut 25 can be inserted into the nut holder 23 with a gap between the inner surfaces of the upper surface 23A and the lower surface 23D of the nut holder 23 and between the inner surfaces of both side surfaces 23B and 23C, and at least between the inner surfaces of both side surfaces 23B and 23C. A screw hole 25 a that extends in the vertical direction and is screwed into the screw shaft 30 is formed in the center portion in the length direction. Further, the outer peripheries 25b and 25c of the end of the nut 25 are covered with annular buffer members 26b and 26c made of an elastic member such as rubber.

  On the other hand, a cross section in which a holder main body 27a that holds the hood leg 21 in a U-shaped cross section and guides and guides the hood leg 21 in the up-and-down direction and mounting flanges 27b that are attached to the side wall 4 at both ends are formed on the inner surface of the side wall 4. A hood leg holder 27 that is hat-shaped and extends in the vertical direction is attached.

  The screw shaft 30 extends coaxially with the hood leg 21, and a base end 30 a is rotatably supported by a thrust bearing 31 mounted and supported on the side wall 4 and the floor 3 by brackets 32 and 33. As shown in FIG. 8, the upper part of the screw shaft 30 passes through the lower screw shaft through hole 24 b and the upper screw shaft through hole 24 a of the nut holder 23 and is inserted into the hood leg 21. Screwed into the screw hole 25a.

  As a result, the nut 25 to which the screw shaft 30 is screwed by the rotation of the screw shaft 30 is slightly swung along with the rotation of the screw shaft 30, and then the respective outer peripheries 25 b and 25 c are passed through the buffer members 26 b and 26 c. The rotation is restricted by contacting the side surfaces 23B and 23C of the nut holder 23. Further, when the nut 25 is screwed by the rotating screw shaft 30, the upper surface 23 </ b> A or the lower surface 23 </ b> D of the nut holder 23 is pressed by the nut 25, and the hood leg 21 moves up or down with respect to the screw shaft 30. At this time, if there is a relative shift between the axis of the screw shaft 30 and the axis of the hood leg 21, the screw shaft 30 is screwed onto the nut holder 23 provided at the lower end of the hood leg 21. The mating nut 25 moves and the axial center of the screw shaft 30 and the axial center of the nut 25 are held coaxially.

  The electric motor 35 is attached to the side wall 4 and the floor 3 by brackets 32 and 33, and rotationally drives the screw shaft 30 via a gear mechanism (not shown). The rotational drive of the screw shaft 30 by the electric motor 35 rotates the screw shaft 30 forward or backward by an up / down operation of a lift switch (not shown) and is screwed into the screw shaft 30 by continuing the up operation or down operation. When the hoist leg 21 continues to be raised or lowered via the nut 25, the nut holder 23, etc., and the raising or lowering operation of the raising / lowering switch is stopped, the nut 25 that is screwed to the screw shaft 30 stops at this position. Retained.

  Further, a descending end stop switch 36 for restricting the descending end of the hood leg 21 is provided by contacting the nut holder 23 descending to the bracket 32, and the ascending nut holder 23 abuts on the lower end of the hood leg holder 27. A rising end stop switch 37 for restricting the rising end of the leg 21 is provided.

  When the lowering nut holder 23 comes into contact with the lowering stop switch 36, the electric power supply to the electric motor 35 is stopped and the rotation is stopped. Similarly, when the ascending nut holder 28 comes into contact with the ascent stop switch 37, the power supply to the electric motor is stopped and the rotation is stopped.

  As shown in FIG. 1, the hood 40 includes a rectangular side portion 40A that is attached to the left and right side hood bone structures 12 of the hood bone structure 11 and covers the side hood bone structures 12, and a front hood bone structure. A rectangular front portion 40B attached to the body 16 and covering the front hood bone structure 16 and a rectangular roof portion 40C attached to the roof portion hood bone structure 17 and covering the roof portion hood bone structure 17 from above. Are integrally formed.

  Next, the operation of the hood device 10 configured as described above will be described.

  For convenience of explanation, as shown by a solid line in FIG. 1, the hood bone structure 11 and the hood 40 supported by the hood bone structure body 11 are raised from the state held at the lowered end position to the raised end position shown by the phantom line. The case will be described. 2 to 8 show a state of the lifting device 20 in which the hood bone structure 11 is held at the lowered end position.

  In a state where the hood bone structure 11 is held at the lowered end position, the four corners of each floor 4, the front end portion 13a and the rear end portion 13b of the right upper longitudinal frame 13, and the left upper longitudinal frame 13 are arranged. The hood leg 21 of each lifting device 20 installed between the front end portion 13a and the rear end portion 13b is held at the lower end position where the nut holder 23 attached to the lower end thereof contacts the lower end stop switch 36. ing.

  In this state, the elevating switch is raised, and each elevating device 20 is driven to rotate the screw shaft 30 forward by the electric motor 35 by continuing the operation. After the nut 25 to be screwed into the screw shaft 30 is slightly rotated by the forward rotation driving of the screw shaft 30, the outer periphery 25b, 25c of each end of the nut 25 is connected to the side surface 23B of the nut holder 23 via the buffer members 26b, 26c. , The rotation is restricted by contacting the inner surface of 23C. At this time, the outer peripheries 25b and 25c of the end of the nut 25 come into contact with the side surfaces 23B and 23C of the nut holder 23 through the buffer members 26b and 26c. Generation of abnormal noise is prevented.

  Further, the nut 25 is screwed upward by the screw shaft 30 that rotates forward, contacts the upper surface 23A of the nut holder 23, pushes up the nut holder 23, and the hood leg 21 coupled to the nut holder 23 follows the hood leg holder 27. To raise the hood bone structure 11.

  When the hood bone structure 11 is pushed up, the extension speed of each lifting / lowering device 20, that is, the amount by which the hood leg 21 is lifted, varies, and the hood bone structure 11 is inclined and the axis of the hood leg 21 and the screw shaft are tilted. When a relative shift occurs with respect to the shaft center of 30, the nut 25 that is screwed into the screw shaft 30 with respect to the nut holder 23 disposed at the lower end of the hood leg 21 by the relative shift in the nut holder 23. The shaft center of the screw shaft 30 and the shaft center of the nut 25 are held coaxially. As a result, the generation of a load due to excessive friction or the like between the screw shaft 30 and the nut 25 that are screwed together is suppressed, and the screw 25 is smoothly fed by the screw shaft 30 that rotates in the forward direction. Rises smoothly.

  Further, in each elevating device 20 continued by the operation of continuously raising the operation switch, the hood leg 21 is screw-fed by rotating the screw shaft 30 by the electric motor 35 in the forward direction, and the hood bone structure 11 is raised. When pushed up to the position, the upper surface 23A of the nut holder 23 attached to the lower end of the rising hood leg 21 comes into contact with the rising end stop switch 37 provided at the lower end of the hood leg holder 27. As a result, when the rise of the nut holder 23 is prevented, the rise of the nut 25 stops, and the rotational torque of the screw shaft 30 screwed into the nut 25 increases, so that the current to the electric motor 35 that drives the rotation gradually increases. When the voltage reaches a predetermined voltage, the lifting switch is activated to stop the rotation of the electric motor 35, and the lifting device 20 holds the hood bone structure 11 and the hood 40 held by the hood structure 11 at the rising end position.

  On the other hand, in order to lower the hood bone structure 11 and the hood 40 held at the raised end position to the lowered end position, the raising / lowering switch is lowered while being held at the raised end position, The elevating device 20 drives the screw shaft 30 to rotate in reverse by an electric motor 35. Due to the reverse rotation driving of the screw shaft 30, the nut 25 to which the screw shaft 30 is screwed is slightly rotated along with the reverse rotation of the screw shaft 30, and the outer periphery 25 b, 25 c of each end of the nut 25 is passed through the buffer members 26 b, 26 c. Thus, the rotation is restricted by contacting the inner surfaces of the side surfaces 23C and 23B of the nut holder 23, respectively. At this time, the outer peripheries 25b and 25c of the end of the nut 25 abut against the side surfaces 23C and 23B of the nut holder 23 through the buffer members 26b and 26c. Generation of abnormal noise is prevented.

  Further, the nut 25 is screwed downward by the screw shaft 30 rotating in the reverse direction, the nut holder 23 having the upper surface 23A supported by the nut 25 is lowered together with the nut 25, and the hood leg 21 coupled to the nut holder 23 is the hood leg. The hood bone structure 11 and the hood 40 are lowered by the contraction of each lifting device 20 along the holder 27.

  When the hood bone structure 11 is lowered, the contraction speed of each lifting device 20, that is, the amount by which the hood leg 21 is lowered, varies, and the hood bone structure 11 is inclined and the shaft of the hood leg 21 of the lifting device 20 is tilted. When a relative shift occurs between the core and the axis of the screw shaft 30, the nut 25 that is screwed into the screw shaft 30 with respect to the nut holder 23 disposed at the lower end of the hood leg 21 due to the relative shift. By moving through the nut holder 23, the axis of the screw shaft 30 and the axis of the nut 25 are held coaxially. As a result, the generation of a load due to excessive friction or the like is suppressed between the screw shaft 30 and the nut 25 that are screwed together, and the screw 25 is smoothly fed by the screw shaft 30 that rotates in the reverse direction. It descends smoothly.

  Further, when the hood leg 21 is lowered by the reverse rotation of the screw shaft 30 of each lifting and lowering device 20 by the descending operation of the operation switch continuously performed and the hood bone structure 11 reaches the descending end position, the hood leg that descends. A lower surface 23 </ b> D of the nut holder 23 attached to the lower end of 21 comes into contact with the descending end stop switch 36. As a result, the power supply is stopped, the rotation of the conduction motor 35 is stopped, and the hood bone structure 11 and the hood 40 held by the hood structure 11 are held at the lower end position by the elevating devices 20.

  Further, when the operation of the elevating switch is stopped by the forward / reverse rotation of the screw shaft 30 by the electric motor 35 of each elevating device 20 by the elevating or lowering operation of the elevating switch 20 The rotation of the screw shaft 30 is stopped and the nut 25 that is screwed into the screw shaft 30 is prevented from rising and descending, and the hood structure 11 and the hood structure 11 are held in this position. The hood bone structure 11 and the hood 40 are raised or lowered by forward / reverse rotation of the screw shaft 30 by the electric motor 35 of each lifting / lowering device 20 again by raising / lowering the raising / lowering switch.

  Therefore, when the hood bone structure 11 and the hood 40 are raised or lowered by extension or contraction of each lifting / lowering device 20, a difference occurs in the extension speed or contraction speed of each lifting / lowering device 20, and the amount of movement of each hood leg 21. Even if the hood bone structure 11 is inclined due to the variation of the hood, and the shaft center of the hood leg 21 and the shaft center of the screw shaft 30 of all or any of the lifting devices 20 are displaced, The nut 25 screwed onto the screw shaft 30 moves relative to the nut holder 23 disposed at the lower end, and the shaft center of the screw shaft 30 and the shaft center of the nut 25 are held coaxially. Thereby, the screw feed of the nut 25 by the rotation of the screw shaft 30 can be performed smoothly, and the hood leg 21 coupled to the nut holder 23 can be smoothly raised and lowered by the screw feed of the nut 25 in the nut holder 23. A smooth rise and fall of the hood 40 can be obtained by raising and lowering the hood bone structure 11.

  In addition, variations in the extension speed and the contraction speed are allowed between the lifting devices 20, and the required accuracy of the lifting devices 20 and the hood bone structure 10 can be relaxed. The assembly accuracy of the structure 10 and the required accuracy of each part are alleviated, a hood device can be configured at low cost, and an increase in cost can be suppressed.

  Further, since the buffer members 26b and 26c are disposed on the outer circumferences 25b and 25c of the end portions of the nut 25 of each lifting device 20, the nut 25 and the nut holder 23 are directly contacted when the lifting device 20 is extended or contracted. Generation of abnormal noise due to contact is avoided.

  Further, since the buffer members 26b and 26c are arranged on the outer circumferences 25b and 25 of the end portions of the nut 25, vibrations are generated in the hood 40 and the hood frame structure 11 due to vibration caused by traveling and wind pressure acting on the hood 40. Direct contact between the nut holder 23 provided on the hood leg coupled to the hood bone structure 11 and the nut 25 screwed to the screw shaft 30 is avoided, and generation of abnormal noise can be avoided, and the hood The resonance of the bone structure 11 and the hood 40 can be suppressed.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of invention. For example, in the above embodiment, the nut holder 23 is formed in a rectangular cylinder shape having the upper surface 23A, both side surfaces 23B and 23C, and the bottom surface 23D, but the nut holder 23 may be formed in a cylindrical shape. Further, in the above-described embodiment, the hood elevating device 20 is disposed at each of the four corners of the hood device 10, but the elevating device 20 is disposed at the two opposite corners and can be extended and contracted at the other two opposite corners. A member can also be provided.

It is a rear part perspective view of the lorry where the hood device provided with the lifting device of the platform hood concerning this embodiment was provided in the loading platform. It is an enlarged view of the loading platform part of FIG. 3 is a cross-sectional view taken along the line II of FIG. It is a perspective view perspective view of a raising / lowering apparatus. It is the A section enlarged view of FIG. It is a B arrow view of FIG. It is the C section enlarged view of FIG. It is the II-II sectional view taken on the line of FIG. It is sectional drawing which shows the principal part of the raising / lowering apparatus of the conventional loading platform hood.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lorry car 2 Cargo bed 3 Floor 4 Side wall 10 Top device 11 Top bone structure 20 Lifting device 21 Top leg 23 Nut holder 23A Upper surface 23D Lower surface 24a Upper screw shaft through hole 24b Lower screw shaft through hole 25 Nut 25a Screw hole 25b, 25c End outer periphery 26b, 26c Buffer member 27 Cover leg holder 30 Screw shaft 30a Base end 31 Thrust bearing 35 Electric motor (screw shaft rotation drive means)
36 Lower end stop switch 37 Upper end stop switch 40 Top

Claims (3)

In the lifting device for the loading platform hood, which is arranged between the floor of the loading platform and the hood framework structure that holds the hood and lifts the hood framework structure,
A cylindrical hood leg having an axis centered at the upper end and coupled to the hood bone structure and extending in the vertical direction;
An upper screw shaft through hole that is coupled to the lower end of the hood leg and extends so as to intersect with the axis of the hood leg is formed in the upper surface and communicated with the hood leg on the upper surface, and the upper screw shaft through hole is formed on the lower surface. A nut holder with a lower screw shaft through hole facing the
A screw whose base end is rotatably supported by the floor and extends in the vertical direction, and whose upper part passes through the lower screw shaft through hole and the upper screw shaft through hole of the nut holder and is inserted into the hood leg. The axis,
A screw hole that is screwed into the nut shaft is formed in the center portion, and is accommodated in the nut holder with a gap between the inner surface of the nut holder, and the end portion contacts the inner surface of the nut holder and rotates. Nuts that are regulated,
Screw shaft rotation driving means for driving the screw shaft to rotate forward and backward, and
Lifting device for loading platform hood characterized by comprising: The cargo bed has a side wall extending upward from a side edge of the floor;
A hood leg holder disposed on the side wall for guiding the hood leg in a vertical direction;
An ascending end stop switch for restricting the ascending end position of the hood leg by abutting the nut holder disposed at the lower end of the hood leg holder and ascending;
A descent end stop switch that regulates the descent end position of the hood leg by abutting the nut holder disposed on the floor and descent;
The lifting device for a cargo bed hood according to claim 1, comprising:   The lifting device for a platform hood according to claim 1 or 2, wherein the outer periphery of the end of the nut is covered with an annular buffer member made of an elastic material.

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