JP2020055435A - Transport vehicle - Google Patents

Abstract

To prevent floating of a swing frame (hence, load platform) as a result of lengthening of a raising/lowering cylinder due to external force received in the process of unloading or loading in a transport vehicle designed such that the front part of the load platform is engaged with the top of a swing frame, pivotally supported on the rear part of a vehicle body, so as to be movable forward and backward, the swing frame is allowed to erect and swing together with the load platform by means of the raising/lowering cylinder, and the load platform can be driven between the furthest backward inclined position where the rear end of the load platform is in contact with the ground and the furthest forward loading position on the top of the swing frame in a lowered position.SOLUTION: A hydraulic controller C that exerts feed/discharge control for hydraulic oil pressure for a raising/lowering cylinder Cc exerts the feed/discharge control to maintain a shortened state of the raising/lowering cylinder Cc during an unloading process in which a load platform 3 is driven from the furthest forward loading position 3F to the furthest backward inclining position 3R, during loading process in which the load platform 3 is driven from the furthest backward inclining position 3R to the furthest forward loading position 3F, or during the unloading process and the loading process.SELECTED DRAWING: Figure 14

Description

  The present invention relates to a transportation vehicle, particularly to a rear portion of a vehicle body, in which a rear end portion of a swing frame extending in the front-rear direction is pivotally supported so as to be able to swing up and down, and a front portion of a carrier can be moved back and forth by a guide rail on the swing frame. On the other hand, the rear part of the loading platform is supported by the vehicle body so as to be able to swing up and down and move back and forth, and between the swing frame and the vehicle body, an up-and-down cylinder for raising and lowering the swing frame together with the loading platform is interposed. A slide cylinder is provided between the swing frame and the loading platform to move the loading platform back and forth with respect to the swing frame. The present invention relates to a transport vehicle that can be driven between a tilting position and a most advanced mounting position in which a loading platform is mounted substantially horizontally on a swing frame in a prone position.

  The above-mentioned transport vehicle is conventionally known as disclosed in Patent Literature 1, and can be used as a so-called dump truck by swinging a swing frame up and down together with a carrier. In addition, this transport vehicle enables a transported object (for example, a construction machine) to enter the loading platform in a state where the loading platform is lowered to the most backwardly inclined position, and after the loading, moves the loading platform together with the transported product to the most advanced mounting position. It is possible to travel while being loaded on the vehicle body so as to be moved.

Japanese Utility Model Publication No. 7-2302

  In the above-described transport vehicle, in the process of lowering or loading the loading platform, a large external force in the extension direction acts on the undulating cylinder from the loading platform via the swing frame due to the movement of the center of gravity or vibration of the loading platform, and the undulating cylinder is moved. It is possible that the situation will increase somewhat. For example, when the center of gravity of the carrier is biased toward the rear end of the vehicle body (particularly, when the center of gravity of the carrier moves backward from the fulcrum of the swing frame shaft (dump hinge) in the latter half of the unloading process, or the rear end of the carrier begins to float off the ground in the first half of the loading process. A large load in the elongation direction acts on the undulating cylinder from the loading platform, so that the oil chamber on the side of the undulating cylinder connected to the oil tank becomes negative pressure and sucks hydraulic oil from the oil tank. Or the oil leaks in the cylinder (that is, the hydraulic oil leaks from one oil chamber to the other oil chamber through the seal portion of the piston), and the up-and-down cylinder is slightly extended, and this is the loading platform in the unloading process or the loading process. May make the behavior and posture of the robot somewhat unstable.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a transport vehicle that can solve the above problem at once with a simple structure.

  In order to achieve the above-mentioned object, the present invention provides a swinging frame extending in the front-rear direction at a rear portion of a vehicle body so as to be able to swing up and down. The lifting cylinder which supports the rear part of the loading platform so that it can swing up and down and can be moved back and forth by the vehicle body, and between the swing frame and the vehicle body, raises and lowers the swing frame together with the loading platform. A slide cylinder is provided between the swing frame and the loading platform to move the loading platform back and forth with respect to the swing frame. The driving rail can be driven between a predetermined rearward tilting position at which the boarding can be boarded and a most advanced mounting position at which the loading platform is mounted substantially horizontally on the rocking frame in a lying down position. A transport vehicle that gradually tilts the carrier backward as it approaches the last tilting position In addition, the hydraulic control device includes a hydraulic control device that performs supply / discharge control of operating hydraulic pressure to the undulating cylinder, and the hydraulic control device performs a lowering process of driving the loading platform from the most advanced mounting position to the last tilting position, Or, during the loading process of driving the loading platform from the most backwardly tilted position to the most advanced loading position, or during the unloading process and the loading process, the supply / discharge of the loading / unloading cylinder is performed so that the up / down cylinder can be maintained in a contracted state. Controlling is a first feature.

  According to the present invention, in addition to the first feature, the rocking frame and the vehicle body are engaged with each other so as to prevent the rocking frame from lifting up from the vehicle body when the carrier is retracted from the forward limit with respect to the rocking frame. However, a second feature is that a lifting mechanism is provided that releases the engagement in conjunction with the carrier when the carrier is at the forward limit.

  In the present invention, "supporting the rear portion of the loading platform so that it can swing up and down and move back and forth by the body" means that a guide frame pivotally supported by a swing frame on the body so as to be able to swing up and down as in an embodiment described later. The vehicle body includes a body that supports the rear part of the carrier so that it can swing up and down and can move forward and backward by engaging the rear part of the carrier so that it can move back and forth. The concept includes a roller that supports the rear portion of the loading platform so that it can swing up and down and can move back and forth by rollers that are pivotally supported by the upper swing frame.

  According to a first feature of the present invention, a hydraulic control device for controlling supply / discharge of operation hydraulic pressure to an up / down cylinder is provided during a loading / unloading process or a loading process, or during a loading / unloading process and a loading process. Supply / discharge control is performed so that the load carrier can be maintained in a contracted state, so in the process of lowering or loading the load platform, the direction of extension from the load platform to the undulating cylinder via the swing frame due to the movement of the center of gravity or vibration of the load platform. Even when a large external force is applied, the undulating cylinder can be maintained in a contracted state. As a result, it is possible to prevent the swinging frame (and thus the loading platform) from rising slightly from the upper surface of the vehicle body due to the extension of the up-and-down cylinder, thereby destabilizing the behavior and posture of the loading platform (and thus the load) in the unloading process or the loading process. It can be effectively prevented beforehand.

  According to the second feature, in particular, the rocking frame and the vehicle body are engaged with each other so as to prevent the rocking frame from rising from the vehicle body in a state where the loading frame is retracted from the forward limit with respect to the rocking frame. Is equipped with a lifting prevention mechanism that releases the engagement in conjunction with the loading platform when the loading platform is in the forward limit, so that the swinging frame during loading / unloading / loading work without impairing the dumping / lowering function of the loading platform. It is possible to mechanically prevent the (lifting of the bed) from being lifted. Thereby, it is possible to more reliably prevent the lifting, and for example, it is possible to effectively prevent a situation in which the swing frame is suddenly lifted during the unloading / loading operation, the carrier is vibrated, and the load collapses. .

1 is an overall side view showing a transport vehicle according to an embodiment of the present invention. Partial exploded side view of the transport vehicle 2A and 2B show a swing frame and a guide frame of the transporting vehicle, wherein FIG. 2A is a view taken along arrow 3A in FIG. 2, FIG. 2B is a view taken along arrow 3B in FIG. 2, and FIG. View 2A is a cross-sectional view taken along line 4A-4A of FIG. 1; FIG. 2B is an enlarged cross-sectional view taken along line 4B-4B of FIG. 1; FIG. 1C is an enlarged sectional view taken along line 4C-4C of FIG. FIG. 3D shows a relative position of a swing frame, a guide frame, a vehicle body, a carrier, and the like of the transporting vehicle, where (D) is an enlarged sectional view taken along line 5D-5D of FIG. 1 and (E) is 5E-5E of FIG. 1 (F) is an enlarged sectional view taken along line 5F-5F of FIG. 1, and FIG. 1 (G) is an enlarged sectional view taken along line 5G-5G of FIG. 1 is an enlarged sectional view taken along line 6-6 in FIG. Main part front view showing an example of a driver's seat operation panel Circuit diagram showing an example of a hydraulic circuit Block diagram showing an example of a control block diagram of a hydraulic control device It is a side view which shows an example of a dumping process, and a solid line shows the state in which the carrier is in the most upright posture. It is a side view which shows an example of a carrier unloading process, (A) shows the state immediately after unloading starts, (B) shows the state in the middle of unloading, (C) shows the unloading completed state, respectively. Flow chart showing an example of control of the dumping process Flowchart showing an example of control of the dump lowering process Flow chart showing an example of control of the unloading process Flow chart showing an example of control of the loading process Flowchart showing an example of control for emergency mode

  First, an example of a transport vehicle according to the present invention will be described with reference to FIGS. The transport vehicle T of the present embodiment is also used as a transport vehicle for transporting a construction machine K (object to be transported) such as a small bulldozer and a transport vehicle for transporting a load such as earth and sand, that is, a dump truck. In the description of the present specification, the front-rear and left-right directions refer to the front-rear and left-right directions of the transport vehicle T, respectively.

  The transport vehicle T includes a vehicle body F composed of a metal skeleton frame, a cabin 1 disposed in front of the vehicle body F, and a carrier 3 mounted on the vehicle body F behind the cabin 1 via a swing frame 2. And The structure of the swing frame 2 and the related structure of peripheral equipment functionally related thereto will be specifically described later.

  The loading platform 3 is formed in a flat box shape having an open top surface, and has a bottom plate portion 31 formed in a rectangular shape, a front plate portion 32 rising from a front edge and left and right side edges of the bottom plate portion 31, and a left and right side. Side plates 33 and 34 and a rear door 35 that can open and close the rear end opening of the carrier 3 are provided. On the lower surface of the bottom plate portion 31, a pair of left and right lower frames 31b extending in the front-rear direction and parallel to each other are integrally formed so as to project downward, and each lower frame 31b is directed inward (that is, the vertical center line of the vehicle). It is formed in a U-shape in cross section open to the L side).

  In the present embodiment, lower end portions of the left and right side plate portions 33 and 34 are pivotally supported on left and right side edges of the bottom plate portion 31 around the front-rear axis, and the upright state is determined by the left and right side plate portions 33 and 34 and the front plate portion. 32 are held by a clamp mechanism (not shown) which detachably connects the two. If the connection by the clamp mechanism is released at any time, for example, as shown by a two-dot chain line in FIG. The sides can be opened. The left and right side plate portions 33 and 34 may have their lower ends fixed to the bottom plate portion 31.

  The left and right upper and lower ends of the rear door 35 are hinged to left and right side plates 33 and 34, respectively. The lower end of the rear door 35 can be rotated back and forth around, for example, a lower hinge connection portion by a conventionally known hinge switching mechanism (not shown) provided between the rear door 35 and the left and right side plate portions 33 and 34. It is possible to switch at any time between the first switching mode described above and the second switching mode in which the upper end of the rear door 35 can be rotated back and forth around the upper hinge connection portion.

  In the first switching mode, when the transport vehicle T is used, for example, as a construction machine transport vehicle, when the carrier 3 is at a rearwardly inclined position 3R (see, for example, FIG. This is selected when the rear door 35 functions as a crossover plate for allowing the machine K to get on the loading platform 3 smoothly. On the other hand, the above-mentioned second switching mode is selected when the transport vehicle T is used as a dump truck, and according to the selection, the earth and sand from the rear end of the loading platform 3 through the rear door 35 opened by the dumping operation of the loading platform 3 (see FIG. 10). And the like can be smoothly discharged.

  The swing frame 2 includes a swing frame main body 20, a pair of left and right guide rails 21 fixed on the swing frame main body 20 and extending in the front-rear direction, and fixed to a rear portion of the swing frame main body 20 and extending rearward. And a pair of left and right hinge frames 22. The swing frame 2 has its rear end (i.e., hinge frame 22) pivotally supported by the rear end of the vehicle body F via the first pivot P1, whereby the swing frame 2 (therefore, on the swing frame 2). The carrier 3) moves up and down between an upright posture (see the solid line in FIG. 10) inclined backward and backward about the first pivot P1 and a substantially horizontal falling posture (see the solid line in FIG. 1 and the chain line in FIG. 10). It is movable.

  The swing frame main body 20 has a plurality of metal frame members framed vertically and horizontally in a ladder shape, and is formed in a substantially rectangular shape that is long in the front-rear direction. More specifically, it is placed and supported on a seating frame Fc) fixedly mounted on the vehicle body F so as to be capable of coming and going. On the upper surface of the left and right side edges of the swing frame body 20, the lower end surface of the lower surface of the carrier 3 (more specifically, the lower frame 31b described above) is placed and supported so as to be able to come and go.

  A pair of left and right guide rails 21 are formed in a U-shaped cross section that is open inward, and a pair of left and right support brackets 31a projecting downward from the front of the bottom surface of the carrier 3 in the guide rails 21. The rotatably supported guide wheels 36 are engaged with each other so as to be rollable in the front-rear direction. The guide rail 21 has an inclined guide portion 21a inclined upward by a predetermined length rearward from the vicinity of the front end thereof, and a horizontal guide portion 21b extending rearward and horizontally long from the rear end of the inclined guide portion 21a.

  An oscillating device Ac for oscillating the oscillating frame 2 together with the carrier 3 is interposed between the oscillating frame 2 and the vehicle body F. The undulating device Ac includes a link mechanism 23 including a pair of links 23a and 23b each having one end pivotally connected to the intermediate portion of the swing frame 2 and the vehicle body F and the other end pivotally connected to each other, and An undulating cylinder Cc is provided between one link 23a and the vehicle body F. When the up-and-down cylinder Cc extends, the swing frame 2 rises and swings together with the loading platform 3 (ie, dumping operation), and when the cylinder Cc contracts, the swing frame 2 swings up and down with the loading platform 3 (ie, dumping down). Operate.

  Further, a front portion of the guide frame 4 is connected to a rear portion of the swing frame 2 (in the embodiment, a rear end portion of the guide rail 21) so as to be vertically swingable about a second pivot axis P2. The guide frame 4 has an L-shaped left and right side frame portion 40s in a side view and a rear frame portion 40r that connects between the rear end portions (particularly the upper and lower middle portions) of the left and right side frame portions 40s. It is formed in a U-shape. Front and rear guide wheels 41 and 42, which are spaced apart in the front and rear direction, are rotatably supported by the guide frame 4 (more specifically, portions extending in the front and rear directions of the left and right frame portions 40s). The rear guide wheels 41 and 42 are engaged with the lower frame 31b of the carrier 3 so as to be rollable in the front-rear direction.

  Further, a slide cylinder Cs for moving the carrier 3 back and forth with respect to the carrier 2 is interposed between the swing frame 2 and the carrier 3. The rear end of the piston rod of the slide cylinder Cs is pivotally connected to the rear end of the lower surface of the carrier 3 so as to be rotatable around a third pivot line P3. The barrel middle portion of the slide cylinder Cs is connected to the second pivot line. It is pivotally connected so as to be rotatable around P2.

  Thus, as will be described later, the loading platform 3 is moved by the expansion / contraction operation of the slide cylinder Cs alone to a predetermined final retreating position 3R (see FIG. 11C) at which the construction machine K on the ground can enter the loading platform 3. It can be driven between a most advanced mounting position 3F (see a solid line in FIG. 1 and a chain line in FIG. 10) in which the carrier 3 is mounted substantially horizontally on the swing frame 2 which is lying down on the vehicle body F. In this case, the guide rail 21 cooperates with the guide frame 4 to tilt the carrier 3 backward so as to gradually increase the tilt angle as the carrier 3 approaches the retreating position 3R in the latter half of the lowering process of the carrier 3 (FIG. 11). See).

  The rear portion of the guide frame 4 is capable of extending and contracting between a protruding state in which the carrier 3 can be grounded when the carrier 3 is in the last retreating position 3R and a retracted state retracted upward from the protruding state (that is, the posture). (Changeable) jack J is provided. In the following description, the operation of the jack cylinder Cj is referred to as an extension operation for changing the posture of the jack J from the retracted state to the extended state, and the posture is changed from the extended state to the retracted state. May be referred to as a contraction operation.

  The jack J is fixed to the guide frame 4 and extends in the vertical direction. The fixed frame 61 has a rectangular pipe shape in cross section. A pair of left and right movable frames 62 fitted and supported in the fixed frame 61 so as to be slidable up and down. The auxiliary wheel 63 rotatably supported at the lower end of each movable frame 62, a jack cylinder Cj interposed between the movable frame 62 and the guide frame 4 to drive the movable frame 62 up and down, and the jack J are stored in the storage space. A storage sensor J-LS including a limit switch (for example, a proximity switch) capable of detecting that the movable frame 62 is in the state (that is, the movable frame 62 is at the upper limit).

  The storage sensor J-LS includes, for example, a sensor body 73s including a detection element fixed to an upper end portion of the fixed frame 61, and a doc piece 62d that is closely opposed to the sensor body 73s in a contracted state of the jack J (that is, a stored state). In this embodiment, the dowel piece 62d is also used at the upper end of the movable frame 62.

  The fixed frame 61 has a pair of left and right sides, and is fixed to the inner surfaces of the left and right frame portions 40s (more specifically, the rear end portion having a vertically long trapezoidal plate shape) of the swing frame 2. In the jack cylinder Cj, the cylinder barrel is fixed to the left and right intermediate portion of the rear frame portion 40r of the guide frame 4, and the lower end of the piston rod is pivotally connected to a horizontal connecting member 64 connecting the lower end portions of the left and right movable frames 62. It is connected.

  Further, the transport vehicle T engages the rocking frame 2 and the vehicle body F with each other so as to prevent the rocking frame 2 from lifting up from the vehicle body F when the carrier 3 is retracted from the forward limit with respect to the rocking frame 2. And a lifting prevention mechanism 50 that releases the engagement in conjunction with the carrier 3 when the carrier 3 is at the forward limit.

  In the present embodiment, the lifting prevention mechanism 50 is provided with a locking pin 54 fixed to the vehicle body F and a pivot 51p pivotally movable in the upper and lower middle portions of the swing frame body 20 so as to be able to swing back and forth. Is between a lock position (see each chain line in FIG. 1 and each solid line in FIG. 11) that can be locked to the lock pin 54) and an unlocked position (see each solid line in FIGS. 1 and 10) that cannot be locked. , A lock spring 52 as urging means for constantly urging the lock member 51 to the lock position side (ie, clockwise in FIG. 1), and the lock member 51 fixed to the loading platform 3. And an unlockable member 53 that can be engaged and disengaged at the upper end of the lock. The lock release member 53 is engaged with the lock member 51 so as to move and hold the lock member 51 to the lock release position in conjunction with the advance of the carrier 3 from the position immediately before the forward limit to the swing frame 2 to the forward limit. I do.

  Thus, when the lock member 51 is separated from the unlocking member 53 and released, the lock member 51 is urged by the lock spring 52 and held at the lock position, thereby being locked by the vehicle body F (the locking pin 54). This makes it possible to prevent the swing frame 2 from rising from the vehicle body F. In addition, the lock member 51 pivots counterclockwise to the unlocked position against the lock spring 52 in conjunction with the approach and arrival of the loading platform 3 toward the forward end, whereby the rocking via the lock member 51 is performed. The locked state between the frame 2 and the vehicle body F is released. By this unlocking, there is no fear that the lifting prevention mechanism 50 may become an obstacle when the swing frame 2 swings up and down with the carrier 3 in a later-described dumping / lowering process of the carrier 3.

  Further, between the carrier 3 and the swing frame 2, a forward limit sensor S-LS including a limit switch (for example, a proximity switch) capable of detecting a state where the carrier 3 is at the forward limit relative to the swing frame 2 is provided. The forward limit sensor S-LS includes, for example, a sensor body 71s including a detection element fixed to one of the swing frame 2 (that is, the side frame portion of the swing frame body 20) and the carrier 3 (that is, the lower frame 31b). , And a dowel piece 71d fixed to one of the other. The dowel piece 71d is in close proximity to the sensor main body 71s when the carrier 3 is in the forward limit or near the front of the swing frame 2, whereby the sensor main body 71s is in the detection (ie, on) state.

  A landing sensor F-LS is provided between the swing frame 2 and the vehicle body F to detect that the swing frame 2 is lying down on the vehicle body F. The landing sensor F-LS includes, for example, a sensor body 72s including a detection element fixed to one of the vehicle body F (the seating frame Fc) and the swing frame 2 (that is, the side frame portion of the swing frame body 20). And a dowel piece 72d fixed to one of the other. The dorsal piece 72d faces the sensor main body 72s in a state where the swing frame 2 is lying down on the vehicle body F (the seating frame Fc), whereby the sensor main body 72s is in the detection (ie, on) state.

  The operation panel 10 in the cabin 1 is provided with a plurality of switches that can be operated by a worker (for example, a driver) at any time, and these switches include a power switch P-SW, a power take-out switch PTO-SW, and an ON switch. A dump raising switch SW1 for swinging the carrier 3 together with the swing frame 2 in the upright direction by being operated, and the carrier 3 swinging together with the swing frame 2 in the falling direction by being turned on. And a lowering switch SW3 for driving the carrier 3 from the most advanced mounting position 3F to the last retreating and tilting position 3R (ie, performing the lowering step) by being turned on. At least a loading operation switch SW4 for driving the loading platform 3 from the last tilting position 3R to the most advanced loading position 3F (ie, executing the loading process) by being operated. It is.

  The power switch P-SW is for turning on the power to the electronic control unit EC at any time, and the power take-off switch PTO-SW is for turning on / off the power take-off device (PTO) of the vehicle at any time. In this power connection state, the output of the vehicle-mounted engine is transmitted to a hydraulic pump PO, which will be described later, so that the hydraulic pump PO is driven.

  In the present embodiment, each of the operation switches SW1 to SW4 is constituted by a momentary switch that is turned on only when the operator presses it and automatically returns to the off operation when the operator releases the hand. The operation and the off operation may be configured by an alternate switch that can be selectively fixed. Further, in the present embodiment, each operation of raising and lowering the dump truck and lowering and loading of the loading platform 3 is performed separately by the dedicated switches SW1 to SW4. A single toggle switch integrating the functions of the switches SW1 and SW2 may be used to enable the operation of switching between dumping up (ON), OFF, and dumping down (ON), or switches SW3, 4 for unloading and loading. A single toggle switch that combines the functions described above may be used to enable switching operation between unloading (on), off, and loading (on).

  Further, the operation panel 10 is provided with error display means 11 (for example, a group of display lamps) for notifying an operator of an abnormality during the execution of the process (that is, displaying an error). It is desirable that the display mode of the error display means 11 is such that, for example, an error state in the early stage of the start and an error state in the middle of the process can be easily identified from a difference in color or a difference in blinking. It is desirable that the display mode be such that it is possible to identify an error state caused by a failure of -LS, S-LS, J-LS.

  In the present embodiment, the abnormality notification by the error display means 11, that is, the error display, is performed in steps S5, S10, and S15 in the flowcharts (FIGS. 12 to 15) of the dump raising, lowering, lowering, and loading steps described later. , S26, S27, S29, S45, S56, S65, S81, and S82.

  Further, the operation panel 10 is used in place of or in addition to the error display means 11 for notifying the operator of an abnormality during the execution of the process or alerting the operator about a specific operation (for example, the operation of storing the jack J). An alarm sound generating means 12 (for example, an alarm buzzer, a speaker, etc.) is provided. It is desirable that the alarm sound from the alarm sound generation means 12 be capable of easily distinguishing the content and extent of the abnormality from the tone color and volume of the alarm sound, for example, or an error state in place of or in addition to a simple alarm sound. May be emitted.

  FIG. 8 shows an example of a hydraulic circuit HC for controlling the supply and discharge of the operating hydraulic pressure to the up-and-down cylinder Cc and the slide cylinder Cs. As shown in FIG. 9, the hydraulic circuit HC, various control valves V1 to V5 in the hydraulic circuit HC, various switches P-SW, PTO-SW, SW1 to SW5, E-SW, and various sensors F- The hydraulic control device C of the present invention is configured by the electronic control device EC connected to the LS, S-LS, and J-LS.

  The hydraulic circuit HC includes a hydraulic pump PO that sucks and pumps oil in the oil tank TA, and a first electromagnetic unit SOL1 for selecting a dumping operation that guides the discharge side of the hydraulic pump PO to the extending oil chamber 100 of the undulating cylinder Cc. A first control valve V1 having a second electromagnetic portion SOL2 for selecting jack contraction for guiding the discharge side to the contraction oil chamber 101 of the jack cylinder Cj, and an extension oil chamber 100 for the undulating cylinder Cc are guided to the oil tank TA. A normally-closed second control valve V2 having a third electromagnetic portion SOL3 for selecting a dump lowering that connects the return oil passage, and extending oil chambers 102 of the jack cylinder Cj and the slide cylinder Cs to connect the discharge side of the hydraulic pump PO to the discharge side. , 103, and a fourth electromagnetic unit SOL4 for selecting a jack extension / rear slide leading to the oil chamber 104 for contraction of the slide cylinder Cs. And a third control valve V3 having L5.

  In the oil passage between the third control valve V3 and the oil chambers 103 and 104 of the slide cylinder Cs, the space between the contraction oil chamber 104 of the slide cylinder Cs and the oil tank TA is normally shut off, and the jack cylinder Cj is connected. A counter balance valve Vcb is provided to start the extension operation of the slide cylinder Cs by opening the valve in response to the extension limit being reached and the operating oil pressure rising to a predetermined value or more. That is, the counter balance valve Vcb causes the jack cylinder Cj to extend first and reaches the extension limit before the extension operation of the slide cylinder Cs starts, and the contraction of the jack J and the forward movement of the carrier 3 are performed in this order. To control the sequence.

  The electronic control unit EC is based on operation inputs to the various operation switches P-SW, SW1 to SW4 and the emergency mode switch E-SW, and detection results of the various sensors F-LS, S-LS, J-LS. The control unit controls the electromagnetic units SOL1 to SOL5 of the control valves V1 to V3 according to a preset and stored control program to control the supply and discharge of the operating oil pressure to and from the cylinders Cc, Cs and Cj (therefore, the control of the cylinders Cc, Cs and Cj Operation control). Thereby, the transport vehicle T can execute the dump raising / lowering process, the loading / unloading process of the carrier 3 and the loading process.

The basic operations of the dump raising / lowering process, the loading / unloading process of the carrier 3 and the loading process controlled by the above-described hydraulic control device C will be described in order. Each process is performed in a state where the power switch P-SW is turned on and the power take-out switch PTO-SW is set to the PTO connection state. In this state, all the operation switches SW1 to SW4 are turned on. If not, the electromagnetic units SOL1 to SOL5 of each of the control valves V1 to V3 are in a non-excited state, and each process is in a standby state.
[Basic operation of dumping process]
When the dump raising operation switch SW1 is turned on, the discharge side of the hydraulic pump PO communicates with the extension oil chamber 100 of the up-and-down cylinder Cc by exciting the first electromagnetic unit SOL1 of the first control valve V1. As a result, the undulating cylinder Cc extends, and the swing frame 2 (therefore, the loading platform 3) swings in the upright direction as shown in FIG. The object flows down from the rear end under its own weight and is discharged.

Also, when the dumping operation switch SW1 is turned off during the dumping operation (that is, when the operator releases the switch SW1), the first control valve V1 returns to the neutral position, and the undulating cylinder Cc extends. After stopping, the swing frame 2 (therefore, the bed 3) stops at the current raised position.
[Basic operation of dump lowering process]
When the dump-lowering switch SW2 is turned on in the above-described dump-up state, the electromagnetic unit SOL3 of the second control valve V2 is excited, so that the extending oil chamber 100 of the undulating cylinder Cc communicates with the oil tank TA. I do. As a result, the up-and-down cylinder Cc to which the weight of the loading platform 3 acts contracts, and the swing frame 2 (therefore, the loading platform 3) swings in the falling direction, that is, the dumping lowering operation, and finally, as shown in FIG. Then, the vehicle stops in a horizontal prone position on the vehicle body F.

If the switch SW2 for dumping lowering operation is turned off during the lowering of the dump (that is, the operator releases the switch SW2), the second control valve V2 returns to the neutral position, and the extension cylinder Cc extends. The oil chamber 100 and the oil tank TA are shut off. As a result, the retracting operation of the up-and-down cylinder Cc is stopped, and the swing frame 2 (therefore, the bed 3) is stopped at the lowered position at that time.
[Basic operation of unloading process]
When the unloading operation switch SW3 is turned on, the fourth electromagnetic portion SOL4 of the third control valve V3 is excited, so that the discharge side of the hydraulic pump PO moves to the respective extension oil chambers 103 of the slide cylinder Cc and the jack cylinder Cj. Communicate with 102. At this time, by the operation of the above-described counterbalance valve V4, sequence control is performed such that the extension of the slide cylinder Cs starts after the jack cylinder Cj first extends and reaches the extension limit.

  During this time, in conjunction with the extension of the slide cylinder Cs, the carrier 3 moves rearward along the swing frame 2 (guide rail 21) and the guide frame 4 as shown in FIGS. 11A and 11B. In particular, the front portion of the loading platform 3 is slightly lifted based on the front inclined form of the guide rail 21 and the rearward swing of the guide frame 4. Then, as the guide wheel 36 at the front of the carrier 3 approaches the second pivot axis P2 with the subsequent rearward movement of the carrier 3, the rearward descending angle of the carrier 3 gradually increases, and finally, as shown in FIG. As shown, the slide cylinder Cs stops extending at the last retreating position 3R where the rear end of the loading platform 3 is in contact with the ground.

In this state, the rear door 35 of the loading platform 3 is swung rearward around the lower hinge connecting portion as shown in FIG. 11C to form a crossover plate, and the construction machine K (the object to be transported) can be loaded on the loading platform 3.
[Basic operation of loading process]
When the loading operation switch SW4 is turned on in the unloading state of the carrier 3, the fifth electromagnetic portion SOL5 of the third control valve V3 is excited, so that the discharge side of the hydraulic pump PO compresses the contraction oil of the slide cylinder Cc. It communicates with the chamber 104. As a result, the loading platform 3 moves forward along the swing frame 2 (guide rail 21) and the guide frame 4 in conjunction with the contraction of the slide cylinder Cs. The posture gradually changes to a horizontal posture by cooperation (that is, changes as shown in FIG. 11 (C) → (B) → (A) → FIG. 1). Then, when the carrier 3 finally reaches the forward limit with respect to the swing frame 2, the slide cylinder Cs stops contracting at the most advanced mounting position 3F.

  Next, the second electromagnetic portion SOL2 of the first control valve V1 is excited to communicate with the contraction oil chamber 101 of the jack cylinder Cj. Thereby, the jack cylinder Cj contracts, and the retracting operation of the jack J ends at the contraction limit.

Next, a description will be given with reference to flowcharts of FIGS. 12 to 16 showing an example of a control procedure of each of the above-described steps. In addition, the flowchart of each process is such that the power switch P-SW is turned on to energize the electronic control device EC, and the power take-out device is set to the power-connected state by the power take-out switch PTO-SW. It is executed based on a control program for storage.
[Control example of dumping process]
In FIG. 12, when the switch SW1 for dumping operation is turned on in step S1, the process proceeds to step S2 to determine whether any of the other operation switches SW2 to SW4 is being operated. Goes to step S3, enters a full stop state in which all the cylinders Cc, Cs, Cj are emergency stopped, and returns to the standby state again. Here, the emergency stop refers to a state in which the expansion and contraction of all the cylinders Cc, Cs, and Cj are stopped. In the present embodiment, the discharge side of the pump Po is controlled by setting all the electromagnetic units SOL1 to SOL5 to non-excitation. It does not communicate with any of the oil chambers Cc, Cs, Cj, and therefore indicates a state in which all cylinders Cc, Cs, Cj do not expand or contract. Note that all the cylinders Cc, Cs, and Cj may be prevented from expanding and contracting by blocking the discharge of oil from each oil chamber to the tank T.

  If it is determined in step S2 that the other operation switches SW2 to SW4 are not being operated, the process proceeds to step S4, in which the start determination is performed, that is, both the storage sensor J-LS and the forward limit sensor F-LS are turned on (i.e., It is determined whether the jack J is in the stored state and the carrier 3 is in the forward limit. If neither is on, the process proceeds to step S5 to display an error, the dumping process is not started, and the process enters a standby state.

  If both the sensors J-LS and F-LS are on in step S4, the process proceeds to step S6 to excite the first electromagnetic unit SOL1 of the first control valve V1, thereby extending the undulating cylinder Cc. Since the supply hydraulic pressure is supplied, the rocking motion of the carrier 3 in the rising direction, that is, the dumping operation is started.

  Next, in step S7, it is checked whether both sensors J-LS and F-LS are on during the dumping operation (that is, one of both sensors J-LS and F-LS is off and the jack is stored). It is checked whether it is protruding from the posture or whether the carrier 3 is displaced rearward). If any of them remains on, the process proceeds to step S8, and it is determined again whether the dumping operation switch SW1 is on. You. If the dumping operation switch SW1 is on, the process returns to step S7. If the switch SW1 is not on, the process proceeds to step S9. In step S9, the extension of the up-and-down cylinder Cc is stopped by the non-excitation of the first electromagnetic unit SOL1 excited in step S6, and the dumping operation is stopped.

When both sensors J-LS and F-LS are not turned on in step S7, the process proceeds to step S10, an error is displayed, and the process further proceeds to step S9 to stop the dumping operation. It goes into a standby state.
[Control example of dump lowering process]
In FIG. 13, when the switch SW2 for dump lowering operation is turned on in step S11, the process proceeds to step S12, where it is determined whether any of the other operation switches SW1, 3, and 4 is being operated. For example, the process proceeds to step S13, where all the cylinders Cc, Cs, Cj are brought to an emergency stop state in which the cylinders are emergency-stopped, and return to the standby state again.

  If it is determined in step S12 that the other operation switches SW1, 3, and 4 are not being operated, the process proceeds to step S14, and the start determination is performed, that is, the storage sensor J-LS is turned on (that is, the jack J is stored). Is determined. If it is not on, the process proceeds to step S15 to display an error, the dump lowering process is not started, and a standby state is set.

  If the storage sensor J-LS is ON in step S14, the process proceeds to step S16, in which the operating oil is moved to the slide cylinder Cs by the excitation of the fifth electromagnetic unit SOL5 of the third control valve V3 to advance the slide bed Cs. (That is, hydraulic pressure for contraction) starts to be supplied, whereby the slide cylinder Cs is urged in the contracting direction (that is, the bed 3 is moved in the forward direction). Next, the process proceeds to step S17, where it is determined whether or not the storage sensor J-LS is on, and if it is on, the process proceeds to step S18. Then, in step S18, it is determined whether the forward limit sensor S-LS is on (ie, the forward limit of the carrier 3 relative to the swing frame 2). If it is not on, the process proceeds to step S28; if it is on, the process proceeds to step S19. .

  In this step S19, it is determined whether or not a predetermined preliminary forward time T1 (for example, 0.5 seconds) has elapsed since the forward limit sensor F-LS was determined to be ON in step S18. Returning to S19, if it has elapsed, the process proceeds to Step S21 via Step S20. Then, in step S20, the fifth electromagnetic unit SOL5 excited in step S16 is de-energized, the supply of the contraction hydraulic pressure to the slide cylinder Cs stops, and the forward movement of the carrier 3 with respect to the swing frame 2 stops. Is done.

  In addition, in step S21, the energizing of the third electromagnetic portion SOL3 of the second control valve V2 causes the oil chamber 100 for extension of the undulating cylinder Cc to communicate with the oil tank TA, whereby the undulating cylinder Cc contracts due to its own weight of the carrier 3. Then, the rocking motion of the carrier 3 in the falling direction, that is, the dump lowering operation is started.

  Next, the process proceeds to step S22, where it is determined whether the storage sensor J-LS is on, and if it is on, the process proceeds to step S23. In this step S23, it is determined whether or not the dump lowering switch SW2 is being turned on. If it is on, the process returns to step S22 to continue the dump lowering operation. If not, the process goes to step S24. In step S24, since the third electromagnetic unit SOL3 excited in step S21 is de-energized, the extension oil chamber 100 of the undulating cylinder Cc is cut off from the oil tank TA, and the dump lowering ends. Note that, even if the dump lowering operation switch SW2 is on, the dump lowering ends when the carrier 3 falls down, and in this case, the output hydraulic pressure from the hydraulic pump PO is relieved, that is, returned to the oil tank TA side.

  If it is determined in step S17 that the storage sensor J-LS is off (abnormal), the process proceeds to step S26 via step S25, and returns. That is, in step S25, as in step S20, the slide cylinder Cs contracts and stops, and the forward movement of the carrier 3 stops. In step S26, an error message is displayed, and the dump lowering process is in a standby state.

  If it is determined in step S22 that the storage sensor J-LS is off (abnormal), the process proceeds to step S27 to display an error, and then returns to step S24, where the dump lowering process is in a standby state.

In step S28, the elapsed time from the excitation of the fifth electromagnetic unit SOL5 in step S16 (that is, the forward movement of the carrier 3) is sufficiently long (that is, such that the forward limit sensor S-LS is assumed to have failed). It is determined whether a (long) predetermined failure determination time T2 (for example, 20 seconds) has elapsed, and if not, the process returns to step S17. If it is determined in step S28 that the failure determination time T2 has elapsed, the process proceeds to step S29 to display an error, and then proceeds to step S20. Therefore, even if the forward limit sensor S-LS remains off due to a failure, after the failure determination time T2 has elapsed, the processes of steps S20 to S24 are executed without any trouble until the end of the dump lowering, and the dump lowering process is performed. It is possible to finish.
[Control example of unloading process]
In FIG. 14, when the lowering operation switch SW3 is turned on in step S41, the process proceeds to step S42, where it is determined whether any of the other operation switches SW1, 2, and 4 is being operated. Then, the process proceeds to step S43, where all the cylinders Cc, Cs, Cj are brought to an emergency stop state in which all the cylinders Cc, Cs, Cj are emergency-stopped, and then return to the standby state.

  If it is determined in step S42 that the other operation switches SW1, SW2, and SW4 are not being operated, the process proceeds to step S44 to determine the start, that is, the landing sensor F-LS is turned on (that is, the swing frame 2 is in the vehicle body F). It is determined whether the device is in the state of "landing on the top". If it is not on, the process proceeds to step S45 to display an error.

  If it is determined in step S44 that the landing sensor F-LS is ON, the process proceeds to step S46, and the extension oil chamber 100 of the undulating cylinder Cc is excited by the excitation of the third electromagnetic unit SOL3 of the second control valve V2. Is in communication with the oil tank TA. As a result, the up-and-down cylinder Cc is urged in the contracting direction by the weight of the bed 3, so that the bed 3 is constantly urged and held in the upside down position on the vehicle body F during the unloading process. This state is referred to as “dump reduction” in step S46 of FIG.

  Next, the process proceeds to step S47, where it is determined whether the forward limit sensor S-LS is on (that is, the forward limit of the carrier 3 with respect to the swing frame 2). If it is on, the process proceeds to step S48.

  In this step S48, the supply of the hydraulic oil (that is, the contraction oil pressure) for advancing the carrier 3 to the slide cylinder Cs by the excitation of the fifth electromagnetic unit SOL5 of the third control valve V3 is started. If the loading platform 3 is slightly behind the normal forward limit (in this case, the forward limit sensor F-LS is turned on, that is, the detection range has some width), the loading platform 3 moves forward to the normal forward limit. Moving. Next, the process proceeds to step S49, and a predetermined preliminary advance time T3 (for example, 0.5 seconds) has elapsed since the fifth electromagnetic unit SOL5 was excited in step S48 (that is, from the start of the forward movement of the carrier 3). If it is determined that the time has elapsed, the process proceeds to step S51 via step S50. Then, in step S50, the fifth electromagnetic unit SOL5 is de-energized, the supply of the contraction hydraulic pressure to the slide cylinder Cs is stopped, and the forward movement of the carrier 3 is stopped.

  In step S51, the discharge side of the hydraulic pump PO communicates with the respective extension oil chambers 103 and 102 of the slide cylinder Cc and the jack cylinder Cj by exciting the fourth electromagnetic unit SOL4 of the third control valve V3. In this case, the extension operation of the jack cylinder Cj and the extension operation of the slide cylinder Cs (that is, the backward movement of the carrier 3) are sequence-controlled in this order by the action of the counterbalance valve V4. The slide cylinder Cs stops extending when the extension limit is reached or the carrier 3 comes into contact with the ground, and at this time, the carrier 3 is at the rearwardly inclined position 3R.

  Steps S52 and S53 are executed during the sequence control. That is, it is determined in step S52 whether the landing sensor F-LS is on (ie, the swing frame 2 is on the vehicle body F) and if it is on (landing state), the process proceeds to step S53. It is determined whether the down switch SW3 is being turned on. If the lowering switch SW3 is on, the process returns to step S52. If not, the process proceeds to step S54, and the fourth electromagnetic unit SOL4 excited in step S51 is de-energized. As a result, the third control valve V3 returns to the neutral position, and the extension of the jack cylinder Cj and the slide cylinder Cs stops.

  Next, the process proceeds to step S55, in which the third electromagnetic portion SOL3 of the second control valve V2 that has been excited in step S46 is not excited, so that the extending oil chamber 100 of the up-and-down cylinder Cc is shut off from the oil tank TA, ie, " The "dump reduction" state is released.

If it is determined in step S52 that the landing sensor F-LS is not on (that is, the swing frame 2 is in the landing state), the process proceeds to step S56, an error message is displayed, and a return is made. The operation of each of the cylinders Cc, Cs, Cj) is in a standby state.
[Example of control of loading process]
In FIG. 15, when the loading operation switch SW4 is turned on in step S61, the process proceeds to step S62, and it is determined whether any of the other operation switches SW1 to SW3 is being operated. Proceeding to step S63, all cylinders Cc, Cs, Cj are in an emergency stop state in which all cylinders are stopped in an emergency, and return to the standby state again.

  If it is determined in step S62 that the other operation switches SW1 to SW3 are not being operated, the process proceeds to step S64 to determine the start, that is, the landing sensor F-LS is turned on (that is, the swing frame 2 is placed on the vehicle body F). It is determined whether or not it is in the landing state. If it is not on, the process proceeds to step S65 to display an error, the loading process is not started, and the process enters a standby state.

  If it is determined in step S64 that the landing sensor F-LS is on, the process proceeds to step S67 via step S66. In step S66, the extension oil chamber 100 of the up / down cylinder Cc is brought into communication with the oil tank TA by exciting the third electromagnetic portion SOL3 of the second control valve V2. Since the pallet 3 is urged in the contraction direction, the loading platform 3 is constantly urged and held in the prone position on the vehicle body F during the loading process. This state is referred to as “dump reduction” in step S66 of FIG. 15 as in step S46 described above.

  In step S67, the supply of hydraulic oil (ie, contraction oil pressure) to advance the carrier 3 to the slide cylinder Cs by excitation of the fifth electromagnetic unit SOL5 of the third control valve V3 is started. It moves forward with respect to the swing frame 2. Next, the process proceeds to step S68, in which it is determined whether the landing sensor F-LS is on (that is, the swing frame 2 is in the landing state). If it is on, the process proceeds to step S69. In this step S69, it is determined whether or not the loading operation switch SW4 is being turned on. If it is on, the process proceeds to step S70, where the forward limit sensor S-LS is turned on (that is, the bed 3 is Is determined.

  Then, in step S70, when the forward limit sensor S-LS is turned on (that is, the bed 3 is in the forward limit), the process proceeds to step S71, where the elapsed time from the turning on of the forward limit sensor S-LS is a predetermined extended forward time T4. (E.g., one second) has elapsed, and if so, the process proceeds to step S73 via step S72. Then, in step S72, the fifth electromagnetic unit SOL5 excited in step S67 becomes non-excited, the supply of the contraction hydraulic pressure to the slide cylinder Cs is stopped, and the forward movement of the carrier 3 is stopped at the forward limit.

  If it is determined in step S70 that the forward limit sensor S-LS is not ON (that is, the platform 3 is not in the forward limit), the process proceeds to step S74, and in step S67, the fifth electromagnetic unit SOL5 is excited (that is, the platform 3 is It is determined whether or not a predetermined failure determination time T2 (for example, 20 seconds) has elapsed since the forward movement was started) (i.e., it is long enough that the forward limit sensor S-LS is assumed to have failed). If not, the process returns to step S68. If it is determined that the time has elapsed, the process proceeds to step S72. Thus, even if the forward limit sensor S-LS has failed and remains off due to a failure, the processing of steps S73 to S80 described below can be performed after the failure determination time T2 has elapsed, and there is no problem until the storage of the jack J is completed. And the loading process can proceed to the end.

  In step S73, the contraction hydraulic pressure is supplied to the jack cylinder Cj by the excitation of the second electromagnetic unit SOL2 of the first control valve V1, the jack J contracts, and the alarm sound generating means 12 such as a buzzer sounds the alarm sound. To alert the worker. Next, the process proceeds to step S75, where it is determined whether the landing sensor F-LS is on (that is, the swing frame 2 is on the vehicle body F), and if it is on, the process proceeds to step S76.

  In this step S76, it is determined whether or not the elapsed time from the start of contraction of the jack cylinder Cj has exceeded a predetermined end determination time T5 (for example, 10 seconds). If not, the process proceeds to step S77. In this step S77, it is determined whether or not the storage sensor J-LS has been turned on (that is, the contraction limit of the jack cylinder Cj). If not, the process returns to step S75, and if it has been turned on, the process proceeds to step S78. In step S78, it is determined whether or not the elapsed time from when the storage sensor J-LS is turned on (that is, the jack cylinder Cj is at the contraction limit) has exceeded a predetermined extended storage time T6 (for example, 0.8 seconds). If so, the process advances to step S80 via step S79.

  The termination determination time T5 is set to be sufficiently longer than the extended storage time T6, and is set to be longer than the required storage time of the jack J (for example, 5 seconds). Further, the extended storage time T6 is set shorter than the required storage time of the jack J.

  Then, in step S79, the second electromagnetic unit SOL2 excited in step S73 is de-energized, and the contraction of the jack cylinder Cj stops, and the alarm sound generation unit 12 also stops the alarm. In step S80, since the third electromagnetic portion SOL3 of the second control valve V2 excited in step S66 is de-energized, the extension oil chamber 100 of the up-and-down cylinder Cc is shut off from the oil tank TA. Compression ”is released.

  If it is determined in step S76 that the elapsed time from the start of the contraction of the jack cylinder Cj has passed the predetermined end determination time T5 (for example, 10 seconds), the process proceeds to step S79, and the warning that the jack cylinder Cj has contracted is issued. The alarm by the sound generating means 12 is stopped.

  If it is determined in step S75 that the landing sensor F-LS is not on (that is, the swing frame 2 is in the landing state), the process proceeds to step S81 to display an error, and then proceeds to step S79. The loading process enters a standby state.

  If it is determined in step S68 that the landing sensor F-LS is not on (that is, the swing frame 2 is in the landing state), the process proceeds to step S82 to display an error, and then proceeds to step S80 via step S83. move on. Then, in step S83, the fifth electromagnetic unit SOL5 excited in step S67 is de-energized, and the contracting operation of the slide cylinder Cs stops, so that the loading step again enters the standby state. Steps S73 to S80 are continued even if the loading switch SW4 is turned off.

  As described above, the control examples of the dump raising / lowering process, the unloading process, and the loading process of the present embodiment have been described. However, according to the present embodiment, the following special effects can be achieved.

  For example, in the dumping lowering process shown in FIG. 13 of the present embodiment, when the dumping lowering switch SW2 is turned on in the standing state of the loading platform 3, the loading platform 3 swinging in the falling direction falls on the vehicle body F. Before the state (particularly, before the dump lowering is started in step S21 in this embodiment), the operating oil is supplied to the slide cylinder Cs for a predetermined preliminary advance time T1 to advance the carrier 3 (step S16). To S20). Accordingly, in a situation where the carrier 3 is slightly lowered (that is, the slide cylinder Cs is slightly contracted due to an oil leak or the like) due to, for example, leaving the carrier 3 in a dumping state for a long time, the dump lowering operation switch SW2 is turned on. Even when the ON operation is performed, the slide cylinder Cs can be moved forward to the forward limit before the lowering of the dump truck 3 is completed. As a result, it is possible to effectively prevent the loading bed 3 from extending beyond the normal mounting position 3F on the vehicle body F in the dump lowering completed state (that is, the running posture of the vehicle). Further, it is not necessary for the operator in the driver's seat to get off and visually check the presence or absence of the overhang of the loading platform 3 each time.

  Further, in the present embodiment, when the carrier 3 is retracted from the forward limit with respect to the swing frame 2, the swing frame 2 and the vehicle body F are engaged with each other so as to prevent the swing frame 2 from rising from the vehicle body F, And, when the carrier 3 is at the forward limit, a lifting prevention mechanism 50 for releasing the engagement in conjunction with the carrier 3 is provided. Therefore, the lifting of the swing frame 2 (therefore, the loading platform 3) during the unloading / loading operation of the loading platform 3 is mechanically prevented without impairing the dumping / lowering function of the loading platform 3, and the collapse of the load is also prevented. It is valid. Further, according to the processes in steps S16 to S20, the slide cylinder Cs can be moved forward to the forward limit (thus disengaging the lifting prevention mechanism 50) before the dumping of the carrier 3 is completed. Is completed, it is possible to effectively prevent the floating prevention mechanism 50 in the engaged state from being interfered with the carrier 3 and damaged.

  By the way, during the traveling of the transporting vehicle T in which the carrier 3 is placed on the body F together with the swing frame 2 when a large inertia force acts on the carrier 3 rearward due to sudden acceleration, the slide cylinder Cs is contracted. Therefore, a large external force acts in the extension direction. Then, when oil leaks from the piston seal portion or the like inside the slide cylinder Cs subjected to the external force, the slide cylinder Cs slightly expands, and the carrier 3 is slightly displaced rearward of the swing frame 2 from the normal advance limit. If the engagement between the swing frame 2 and the vehicle body F by the lifting prevention mechanism 50 is incompletely related to this, if the engagement between the body and the vehicle body F is incomplete, a push-up due to road surface unevenness or the like during traveling in that state. When the loading platform 3 or the like vibrates up and down in response to this, the lifting prevention mechanism 50 may be hardened in an engagement-disabled state. Then, in this state, it is impossible to prevent the swing frame 2 (and thus the carrier 3) from being lifted during the unloading / loading of the carrier 3.

  On the other hand, in the unloading step shown in FIG. 14 of the present embodiment, when the unloading operation switch SW3 is turned on in the down state of the loading platform 3, the forward limit sensor S-Ls detects the forward limit of the loading platform 3. If so, hydraulic oil is supplied to the slide cylinder Cs during the preliminary advance time T3 to advance the carrier 3 before starting the backward movement of the carrier 3 (see steps S47 to S50). Therefore, even when the loading platform 3 is slightly displaced rearward of the swinging frame 2 beyond the normal forward limit when the unloading operation switch SW3 is turned on, before the loading platform 3 is moved backward in step S51, 3 can be reliably moved forward to the normal forward limit, so that the lifting prevention mechanism 50 can be once reset to the disengaged state without fail. As a result, the lifting prevention mechanism 50 can be reliably switched to the engaged state in conjunction with the backward movement of the carrier 3 immediately thereafter, so that the swing frame during the work of lowering and loading the carrier 3 is performed. 2 (therefore, the carrier 3) can be reliably prevented from rising.

  If the forward limit sensor S-Ls is in a non-detection state when the lowering operation switch SW3 is turned on, the bed 3 is moved to a certain extent from the normal forward limit (ie, the detection range of the forward limit sensor S-Ls). It is considered that the lifting prevention mechanism 50 is located on the rear side and the swing frame 2 is engaged with the vehicle body F. Here, the case where the forward limit sensor S-Ls is in the non-detection state when the unloading operation switch SW3 is turned on is, for example, a case where the unloading process is restarted after being temporarily stopped during the unloading process. The lifting prevention mechanism 50 engages the swing frame 2 with the vehicle body F in steps S47 to S50 at the time of starting the lowering process before stopping once. Therefore, unlike the case where the forward limit sensor S-Ls is in the detection state, it is not necessary to move the carrier 3 forward in a special manner. In this case, the step is short-cut from step S47 to step S51, and the work efficiency is increased accordingly. .

  In addition, in the unloading process of the present embodiment, when the unloading operation switch SW3 is turned on in the down state of the loading platform 3, in step S51, after the jack J has been extended from the retracted state to the extended state, the loading platform 3 The extension of the jack cylinder Cj and the extension of the slide cylinder Cs are sequence-controlled in this order so that the backward movement of the cylinder starts. Thus, in the process of lowering the carrier 3 from the running posture of the vehicle, first, the rearward movement of the carrier 3 is started after the extension of the jack J is completed. Together, the safety of the work is further enhanced.

  Further, in the present embodiment, the hydraulic control device C that controls the supply and discharge of the working oil pressure to the up-and-down cylinder Cc causes the up-and-down cylinder Cc to be in the contracted state in the unloading process (FIG. 14) and the loading process (FIG. 15) of the carrier 3. Supply / discharge control (that is, “dump reduction” during steps S46 to S55 and steps S66 to S80) is executed so as to be maintained. Thereby, even when a large external force in the extension direction acts on the undulating cylinder Cc from the carrier 3 via the swing frame 2 due to the movement of the center of gravity or vibration of the carrier 3 in the process of lowering or loading the carrier 3. , The up-and-down cylinder Cc can be maintained in a contracted state. As a result, the up-and-down cylinder Cc slightly extends, and the swing frame 2 (therefore, the loading platform 3) rises from the upper surface of the vehicle body F, so that the behavior or posture of the loading platform 3 (and thus the load) during the unloading process or the loading process is not correct. Stabilization can be effectively prevented in advance.

  In addition, in the above-described unloading process and loading process, the lifting prevention mechanism 50 engages the swing frame 2 and the vehicle body F so as to prevent the swing frame 2 from floating from the vehicle body F. -It is possible to mechanically prevent the swing frame 2 (therefore, the loading platform 3) from being lifted during the loading operation. Thereby, the lifting of the loading platform 3 (oscillating frame 2) is more reliably prevented. For example, the swinging frame 2 is suddenly lifted during the unloading / loading operation, and the loading platform 3 vibrates to cause the load to collapse. And the like can be effectively prevented.

  Further, in the present embodiment, in the loading process (FIG. 15) for driving the loading platform 3 from the most backwardly inclined position 3R to the most forward loading position 3F, the state in which the loading platform 3 is at the forward limit in step S70 is determined by the forward limit sensor S-Ls. Is detected, the supply of hydraulic oil to the slide cylinder Cs for advancing the carrier 3 is continued for the time being until the predetermined extended advance time T4 elapses, and the supply is continued after the elapse of the extended advance time T4. Stop (see steps S71 and S72). Thus, the loading platform 3 can be more reliably positioned at the forward travel limit at the end of the loading process without being affected by the detection error of the forward travel limit sensor S-LS. Can be effectively prevented from unnecessarily overhanging. In addition, since a forward limit sensor with high detection accuracy is not required, cost can be reduced accordingly.

  After the forward limit sensor S-Ls detects that the loading platform 3 is at the forward limit in step S70, the on-operation of the loading operation switch SW4 is canceled before the extended forward time T4 elapses. Until the extension forward time T4 elapses, the supply of the hydraulic oil for advancing the carrier 3 is continued (see steps S70 to S72). As a result, the carrier 3 can be more reliably positioned at the forward limit, and it is possible to more effectively prevent the rear end of the carrier 3 from unnecessarily extending during traveling of the vehicle.

  Furthermore, in the present embodiment, during the contraction operation of the jack J in the loading step shown in FIG. 15, the contraction operation of the jack J is performed in response to the detection of the storage sensor J-Ls that the jack J is in the storage state. Although the process is terminated (see steps S73 to S79), the storage sensor J-Ls determines that the jack J is in the retracted state even after the predetermined termination determination time T5 has elapsed since the jack J started the contraction operation. If no detection has been made (that is, it is determined “yes” in step S76), the contraction operation of the jack J is terminated by shortcut from step S76 to step S79. Thus, even if the storage sensor J-Ls is malfunctioning or malfunctions, the contraction operation is automatically terminated when the termination determination time T5 elapses. Therefore, it is determined whether or not the jack J is in the retracted state. It is no longer necessary for one of the workers to get off the vehicle and check it visually, thereby improving work efficiency.

  In addition, when the storage sensor J-Ls detects that the jack J is in the retracted state during the contracting operation of the jack J in step S73, after the predetermined extended storage time T6 has elapsed from the detection, the jack J is released. The contraction operation is terminated (see steps S77 to S79). As a result, even after the storage sensor J-Ls detects the storage state, the extension can be continued only for the extended storage time T6 just in case of the contraction operation, so that the storage sensor J-Ls is less susceptible to the detection error of the storage sensor J-Ls. , The jack J can be more reliably placed in the stored state.

Furthermore, in this embodiment, when any one of the operation switches SW1 to SW4 is turned on while another operation switch is turned on, all the cylinders Cc, Cs, and Cj are completely stopped (for example, the dumping process). Then, steps S1 to S3, steps S11 to S13 in the dumping step, steps S41 to S43 in the unloading step, and steps S61 to S63 in the loading step). Thereby, it is possible to effectively prevent an unexpected situation from occurring on the carrier 3 or the like due to the simultaneous operation of at least two operation switches SW1 to SW4.
[Example of control for emergency mode]
Incidentally, the hydraulic control device C according to the present embodiment is provided with an optional emergency mode switch E-SW for at least one specific process (in this embodiment, the dump lowering process and the loading process) in order to end the process even during the process. It is configured to be able to shift to the "emergency mode" based on the ON operation of. That is, in this emergency mode, the operation input to the operation switches SW2 and SW4 related to the specific process is ignored, ignoring the detection results of the forward limit / landing / storage sensors S-LS, F-LS, and J-LS. The hydraulic oil supply / discharge control for each of the cylinders Cc, Cs, and Cj can be executed so that the specific process can be terminated without any action.

  The transition to the emergency mode is performed by using a specific sensor preset for each of the operation switches SW2 and SW4 in the specific process (in this embodiment, the storage sensor J-LS and the loading operation when the dump-down operation switch SW2 is turned on). When the switch SW4 is turned on, it is permitted only in a specific error state determined based on the detection mode of the landing sensor F-LS (in this embodiment, each of the sensors J-LS and F-LS is off, that is, a failure state). You. Here, the specific sensor is a sensor that may be difficult to control each of the cylinders Cc, Cs, and Cj so that the bed 3 or the like does not assume a dangerous posture if a failure occurs during the execution of the process. is there.

  The control in the emergency mode is executed in parallel with the control of the dumping, lowering, lowering and loading processes as described above. In particular, when shifting to the emergency mode, control in the emergency mode is given priority over control in each process. Next, an example of control corresponding to the emergency mode will be described with reference to FIG.

  First, in step S101, it is determined whether or not each process is in a standby state at the start of the process or in the middle of each process. If the process is in a standby state, the process proceeds to step S102. In step S102, it is determined whether the emergency mode switch E-SW has been turned on. If the emergency mode switch E-SW has been turned on, the process proceeds to step S103.

  In step S103, it is determined whether the dumping lowering switch SW2 has been turned on. If the dumping operation switch SW2 has been turned on, the process proceeds to step S104, where it is determined whether the storage sensor J-LS is on (that is, the detection state). If the storage sensor J-LS is on, the process proceeds to step S105, and the transition to the emergency mode is permitted. If the storage sensor J-LS is not on, the process proceeds to step S106 to transition to the emergency mode. It is forbidden.

  Thus, when the shift to the emergency mode is permitted in step S105, the determination process of the storage sensor J-LS and the forward limit sensor S-LS during the dump lowering process (FIG. 13) (that is, step S14, In S17, S18, and S22), the dump lowering process is advanced to the end because the control process of the dump lowering process is advanced (for example, steps S14, S16 to S24 are sequentially performed) assuming that they are all in the ON state. .

  Further, for example, when the storage sensor J-LS is normal (ON) and the forward limit sensor S-LS fails (OFF), the shift to the emergency mode is prohibited in step S106. Then, in this case, the dump lowering step is executed according to the control procedure of FIG. Therefore, for example, when it is determined in step S28 that the predetermined failure determination time T2 has elapsed while the forward limit sensor S-LS is off in step S18, the process proceeds to steps S20 to S24, and the dump lowering process is performed. You can proceed to the end.

  On the other hand, if it is determined in step S103 that the dump lowering operation switch SW2 has not been turned on, the process proceeds to step S107, where it is determined whether the loading operation switch SW4 has been turned on. If the operation is not on, the process returns. Then, in step S108, it is determined whether the landing sensor F-LS is on (that is, in the detection state). If it is on, the process proceeds to step S109, where the shift to the emergency mode is permitted. If the LS is not on, the process proceeds to step S110, and the shift to the emergency mode is prohibited.

  Thus, when the shift to the emergency mode is permitted in step S109, the determination process of each of the sensors F-LS, S-LS, and J-LS is performed during the loading process (FIG. 15) (ie, step S64). , S70, S75, and S77), the loading process can be advanced to the end by assuming that the loading process is controlled (eg, steps S64 to S80 are sequentially executed) by regarding the loading process as being in the ON state. .

  Further, for example, when the landing sensor F-LS is normal (ON) and the forward limit sensor S-LS has failed (OFF), the shift to the emergency mode is prohibited in step S110. Then, in this case, the loading step is executed according to the control procedure of FIG. Therefore, for example, if it is determined in step S74 that the predetermined failure determination time T2 has elapsed while the forward limit sensor S-LS remains off in step S70, the process proceeds to steps S72 to S80, and the loading process ends. You can proceed up to.

  Thus, during execution of the specific process (dump lowering process / loading process) by turning on the specific operation switches SW2 and SW4, sensors other than the specific sensor (storage sensor J-LS / landing sensor F-LS) If the forward limit sensor S-LS fails, the cylinders Cc, Cs, and Cj can be safely controlled until the end of the process using only the detection results of the remaining normal sensors J-LS and F-LS. Therefore, even if the emergency mode switch E-SW is turned on, the shift to the emergency mode is prohibited. As a result, it is possible to effectively prevent a situation in which an undesired operation situation occurs due to an operator's operation error due to unnecessary emergency mode switching. That is, the shift to the emergency mode in which the detection results of all the sensors J-LS, F-LS, and S-LS are ignored is narrowed down to a minimum necessary opportunity, thereby improving safety.

  In the present embodiment, when the emergency mode switch E-SW is turned on, each cylinder Cc based on the ON operation of a specific operation switch (that is, the dumping operation switch SW2 and the loading operation switch SW4). , Cs, and Cj, only the supply / discharge control is allowed, so that only the dumping process and the loading process are allowed to shift to the emergency mode. Accordingly, in an error state caused by a failure of a specific sensor (the storage sensor J-LS in the dumping lowering process and the landing sensor F-LS in the loading process) in both of the processes, the emergency mode is switched to the loading mode. Can be returned to a safe running posture, and the vehicle can be driven for the time being.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various design changes can be made without departing from the gist of the present invention.

  For example, in the above-described embodiment, the construction machine K is illustrated as the transported object to be transported by the transport vehicle T. However, the transported object according to the present invention is not limited to the construction machine K, but may be between the carrier 3 and the ground E. The vehicle includes vehicles that can travel on their own (e.g., passenger cars, work vehicles, and the like), and vehicles that cannot travel on their own and various articles (e.g., various mechanical devices, containers, and assembly houses).

  Further, in the above-described embodiment, the loading platform 3 is moved by the extension / contraction operation of the slide cylinder Cs alone, the rearmost tilting position 3R at which the construction machine K (object to be transported) on the ground can get on the loading platform 3, and the loading platform 3 falls down on the vehicle body F. Although the present invention is applied to a so-called single-action transport vehicle that can be driven between a most swingable mounting position 3F in which the loading platform 3 is mounted substantially horizontally on a certain swinging frame 2, the present invention relates to A so-called double action type transport vehicle (for example, see Japanese Utility Model Laid-Open No. 6-18069) in which the cylinder Cc and the slide cylinder Cs cooperate to drive the carrier 3 between the most backwardly inclined position 3R and the most forwardly mounted position 3F. Reference).

  In the above-described embodiment, a single-acting hydraulic cylinder having a single output oil chamber (extension oil chamber 100) is used as the up-and-down cylinder Cc. A double-acting hydraulic cylinder having two output oil chambers may be used. For example, in the embodiment, the operation of “dump reduction” executed in steps S46 and S66 is such that the extension oil chamber 100 of the undulating cylinder Cc communicates with the oil tank TA in the embodiment (that is, the oil chamber 100 extends oil from the extension oil chamber 100). This is executed by causing the oil to flow back to the tank TA, but in the case where the undulating cylinder Cc is of a double-acting type, it is executed by supplying the discharge oil from the hydraulic pump to the contraction oil chamber.

  In the above-described embodiment, in the dump lowering process, the dump lowering is started after a predetermined preliminary advance time T1 has elapsed since the advance limit sensor S-LS was turned on (that is, the forward movement of the carrier 3 is completed). Although the control example (steps S18 to S21) is shown, instead of this control example, dump lowering is started even during the elapse of the preliminary advance time T1, and the carrier 3 falls down on the vehicle body F. Another control example in which the preliminary forward time T1 elapses (that is, the forward movement of the carrier 3 is completed) before the dump lowering stop (step S24) can be implemented. Alternatively, instead of these control examples, the forward movement of the bed 3 may be started after the dumping starts, and the bed 3 may fall down on the vehicle body F after the elapse of the preliminary advance time T1. In this case, A separate sensor for detecting the angle of the carrier 3 or the swing frame 2 at which the forward movement is to be started is separately provided, and the preliminary advance time T1 sufficiently elapses (that is, the carrier 3 is moved) within the descending time from the angle to the falling state. Forward movement is completed).

  Further, in the above-described embodiment, the rear portion of the loading platform 3 is supported by being movably engaged with a guide frame 4 pivotally supported on the swing frame 2 so as to be vertically movable, but the guide frame 4 is omitted. May be. In this case, a roller may be supported on the swing frame 2 or the vehicle body F, and the rear portion of the carrier 3 may be supported on the roller so as to be able to swing up and down and to move back and forth.

  In the above-described embodiment, the jack J is provided on the guide frame 4, but the installation site is not limited to the guide frame 4, and the jack J may be provided on the vehicle body F, for example.

  Also, the jack J of the above-described embodiment is illustrated as an example in which the posture can be changed between an extended state in which the ground can be extended and a stored state retracted upward from the extended state by expanding and contracting the jack J. Is not limited to the embodiment, and may be configured so that the posture can be changed at least between a protruding state in which it can be grounded and a storage state retracted above the protruding state. For example, it is also possible to implement a configuration in which the posture can be changed between the extended state and the retracted state by pivotally supporting an arm extending vertically so as to swing back and forth or left and right.

  Further, in the above-described embodiment, the position of the jack J can be changed between the extended state and the retracted state. However, the jack may be fixed to the guide frame 4 (therefore, the position cannot be changed).

  In the above-described embodiment, the position of the jack J is changed by the actuator (the jack cylinder Cj). However, the structure in which the position of the jack is manually changeable is also possible.

  In the above-described embodiment, the transition to the emergency mode is performed by a specific sensor preset for each of the operation switches SW2 and SW4 in the specific process (in this embodiment, the storage sensor J- LS, a specific state determined based on the detection mode of the landing sensor F-LS when the loading operation switch SW4 is turned on (in this embodiment, the sensors J-LS and F-LS are off, that is, a failure state). An example is shown that is permitted only in an error state. However, the transition condition to the emergency mode can be set under other transition conditions in addition to the condition of the embodiment. For example, in the dumping process and the lowering process, a specific sensor (the storage sensor J-LS or the forward In the specific error state determined based on the detection mode (in the present embodiment, the sensor is off, that is, a failure state) of the landing sensor S-LS and the landing sensor F-LS when the lowering operation switch SW3 is turned on. Only the emergency mode can be set so as to be allowed to shift to the emergency mode. Then, it can be set so that all the steps can be executed in the shifted emergency mode.

  In addition, as a variation corresponding to the emergency mode when the emergency mode switch E-SW is turned on, for example, each of the sensors J-LS, F-LS, and S-LS is a sensor having a self-diagnosis function, The transition to may be set so as to be permitted even in an error state where all the sensors J-LS, F-LS, and S-LS are found to have failed.

C: Hydraulic control device Cc: Up / down cylinder Cs: Slide cylinder F: Body K: Construction machine (transported object)
2 ····· Swing frame 3 ···· Loading platform 3R ··· Last retreating and tilting position 3F ··· Most forward mounting position 4 ······ Guide frame 21 ··· Guide rail 50 .... Floating prevention mechanism

Claims (2)

At the rear of the vehicle body (F), the rear end of a swing frame (2) extending in the front-rear direction is pivotally supported so as to be able to undulate and swing, and a carrier (3) is mounted on a guide rail (21) on the swing frame (2). Of the carrier (3) is supported by the vehicle body (F) so as to be able to swing up and down and to be able to move forward and backward, and between the swing frame (2) and the vehicle body (F). , An up-and-down cylinder (Cc) for raising and lowering the swing frame (2) together with the carrier (3) is interposed, and a carrier (3) is provided between the swing frame (2) and the carrier (3). A slide cylinder (Cs) that moves back and forth with respect to the swing frame (2) is interposed, and the load (3) is moved by the sole operation of the slide cylinder (Cs). And a most forward mounting position where the loading platform (3) is mounted substantially horizontally on the swinging frame (2) in a lying down position. And can be driven between (3F), the guide rail (21), in a transport vehicle bed (3) is tilted back gradually bed (3) closer to the end retreat tilted position (3R),
A hydraulic control device (C) for controlling the supply and discharge of operating hydraulic pressure to and from the hoisting cylinder (Cc);
The hydraulic control device (C) may be configured to move the loading platform (3) from the most advanced loading position (3F) to the last retreating position (3R), or to move the loading platform (3) to the last retreating position. (3R) during the loading process of driving from the most advanced mounting position (3F), or during the unloading process and the loading process, the feeding cylinder (Cc) is maintained in a contracted state so as to maintain the retracted cylinder (Cc) in a contracted state. A transport vehicle that performs emission control.   When the carrier (3) is retracted from the forward limit with respect to the swing frame (2), the swing frame (2) and the vehicle body (F) are configured to prevent the swing frame (2) from rising from the vehicle body (F). The lifting mechanism (50), which engages each other, but releases the engagement in conjunction with the carrier (3) when the carrier (3) is at the forward limit. The transport vehicle described in.