JP2020066406A - Transportation vehicle - Google Patents

Abstract

To provide a transportation vehicle in which a front part of a load-carrying platform is engaged on a rocking frame pivotally supported on a rear part of a vehicle body so that it can move forward and backward, the rocking frame is allowed to stand and be rocked by a derricking cylinder together with the load-carrying platform, and the load-carrying platform can be driven between the most retreated and tilted position where the rear end of the load-carrying platform is grounded and the most forward and mounted position onto the rocking frame in a falling state, which achieves simplification of a structure of a switch for operation and wiring for selectively executing a damp lifting/dropping step and loading/unloading step of the load-carrying platform and reduction in cost.SOLUTION: A control device C that includes a single up switch U-SW capable of operating damp lifting and loading and a forward limitation sensor S-LS of a load-carrying platform 3, and controls a slide cylinder Cs and a derricking cylinder Cc executes the damp lifting step while the forward limitation sensor S-LS detects a state where the load-carrying platform 3 is in forward limitation when the up switch U-SW is input at an up operation position by an operation, but executes the loading step while the forward limitation sensor S-LS does not detect the state.SELECTED DRAWING: Figure 16

Description

  The present invention relates to a transport vehicle, particularly a vehicle body rear portion, which pivotally supports a rear end portion of a swing frame extending in the front-rear direction so that the rear end portion of the swing frame can swing up and down, and at least a front portion of a luggage platform can be moved back and forth on the swing frame. In addition, a hoisting cylinder for hoisting and rocking the rocking frame together with the loading platform is provided between the rocking frame and the vehicle body, and a slide cylinder for moving the loading platform back and forth with respect to the rocking frame between the rocking frame and the loading platform. By operating both the undulating cylinder and the slide cylinder or independently operating the slide cylinder, the loading platform is moved to a predetermined rearward and backward tilting position where an object to be transported on the ground can be loaded on the loading platform, The present invention relates to a transport vehicle that can be driven between a loading platform mounted on a swing frame in a prone state and a substantially horizontal position, and a forwardmost loading position.

  The above-mentioned transport vehicle is conventionally known as disclosed in Patent Document 1, and can be used as a so-called dump truck by swinging the swing frame together with the loading platform. In addition, this transport vehicle enables, for example, the loading of a construction machine (object to be transported) onto the loading platform with the loading platform lowered from the most forward loading position to the last retracted position. It is able to travel while being loaded on the vehicle body by moving to the forward mounting position.

Japanese Utility Model Publication No. 6-18069

  By the way, in the above-mentioned transportation vehicle, a dumping raising step of swinging the loading platform together with the swing frame in the upright direction, a dumping lowering step of swinging the loading platform together with the swing frame in the fall direction, and a forward movement of the loading platform from the most backward tilted position. The loading process to drive to the loading position and the unloading process to drive the loading platform from the most forward loading position to the last receding position are performed by operating inputs to the dump raising / lowering operation switch and the loading / unloading operation switch. I am trying to do it.

  However, the dump raising / lowering operation switch has a raising operation position and a lowering operation position and selectively operates one of the operating positions, while the loading platform unloading / loading operation switch has a lowering operating position. It has a loading operation position and selects and operates any operation position. That is, each operation switch has two operation positions to be selectively operated and input, and includes a dumping up process, a dumping down process, a loading platform loading process, and a loading platform unloading process. Since each operation is individually instructed by an operation input to a corresponding operation position, there is a problem that the switch structure and wiring are complicated as a whole and the cost increases.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a transportation vehicle capable of solving the above problems all at once with a simple structure.

  In order to achieve the above object, the present invention rotatably supports a rear end portion of a swing frame extending in the front-rear direction in a rear portion of a vehicle body, and at least a front portion of a luggage platform is moved forward and backward on the swing frame. A hoisting cylinder that movably engages and that hoists and rocks the rocking frame together with the cargo bed is interposed between the rocking frame and the vehicle body, and the rocking frame is used as the rocking frame between the rocking frame and the cargo bed. By interposing a slide cylinder that moves back and forth, by operating both the undulating cylinder and the slide cylinder, or by operating the slide cylinder independently, it is possible to load the load carrier onto the load carrier. In a transport vehicle capable of being driven between a predetermined rearward tilting position and a forwardmost loading position in which a loading platform is mounted substantially horizontally on the swinging frame in a lying state, the loading platform together with the swinging frame. A dumping process of rocking in the standing direction, A single up switch for instructing execution of a loading step for driving the platform from the last backward tilting position to the most forward loading position by operating input to a predetermined up operating position, and a loading platform for the rocking frame. A forward limit sensor capable of detecting a first state in the forward limit, and a control device capable of operating and controlling the slide cylinder and the undulating cylinder based on an operation input to the up switch and a detection output of the forward limit sensor. And at least when the up switch is operated to the up operation position, the control device executes the dumping step if the forward limit sensor is detecting the first state. However, if the forward limit sensor is not detecting the first state, the first step is to execute the loading step.

  Further, the present invention rotatably pivots a rear end portion of a swing frame extending in the front-rear direction to a rear portion of a vehicle body, and engages at least a front portion of a cargo bed on the swing frame so as to be movable back and forth. A hoisting cylinder for hoisting and rocking the rocking frame together with the cargo bed is interposed between the rocking frame and the vehicle body, and a slide cylinder for moving the cargo bed back and forth with respect to the rocking frame is interposed between the rocking frame and the cargo bed. By interposing, activating both the undulating cylinder and the slide cylinder or operating the slide cylinder independently, the loading platform is moved to a predetermined rearward receding position at which a ground object can be loaded on the loading platform. In a transporting vehicle capable of being driven between a forwardmost loading position where a loading platform is mounted substantially horizontally on the swinging frame in a lying state, the loading platform is swung in the lying down direction together with the swinging frame. Dump lowering process and loading platform at the most forward loading position A single down switch for instructing execution of the lowering step of driving from the rear to the last tilting position by an operation input to a predetermined down operation position, and a second state in which the swing frame is laid down on the vehicle body. At least, and a control device capable of controlling the operation of the slide cylinder and the undulating cylinder based on the operation input to the down switch and the detection output of the landing sensor. When the down switch is operated and input to the down operation position, the control device executes the unloading step if the landing sensor is detecting the second state. A second feature is that the dump lowering step is executed when the sensor is not detecting the second state.

  Further, according to the present invention, a rear end portion of a swing frame extending in the front-rear direction is pivotally supported on a rear portion of a vehicle body so as to be capable of swinging up and down, and at least a front portion of a luggage carrier is engaged on the swing frame so as to be movable back and forth. A hoisting cylinder for hoisting and rocking the rocking frame together with the cargo bed is interposed between the rocking frame and the vehicle body, and a slide cylinder for moving the cargo bed back and forth with respect to the rocking frame is interposed between the rocking frame and the cargo bed. By interposing, activating both the undulating cylinder and the slide cylinder or operating the slide cylinder independently, the loading platform is moved to a predetermined rearward receding position at which a ground object can be loaded on the loading platform. A dump truck for swinging the loading platform together with the swinging frame in an upright direction in a transporting vehicle capable of being driven between the swinging frame and the most forwardly mounted position where the loading platform is mounted substantially horizontally on the swinging frame. Lifting process and loading platform to the last tilted position From the dumping step of driving the loading step of driving from the most forward mounting position to the predetermined forward operation position by operating input to a predetermined up operation position, and swinging the loading platform together with the swing frame in the fall direction, A single up / down switch capable of instructing execution of the unloading process for driving the loading platform from the most forward movement mounting position to the final retracted position by operating input to a predetermined down operation position, and the loading platform moving forward with respect to the rocking frame. A forward limit sensor capable of detecting a first state in a limit, a landing sensor capable of detecting a second state in which the swing frame is lying down on the vehicle body, the up operation position of the up / down switch, and Control capable of controlling operation of the slide cylinder and the undulating cylinder based on each operation input to the down operation position and each detection output of the forward limit sensor and the landing sensor At least, the control device includes the dumping step if the forward limit sensor is detecting the first state when the up / down switch is operated and input to the up operation position. When the forward limit sensor is not detecting the first state, the loading step is performed, and when the up / down switch is operated and input to the down operation position, the loading operation is performed. If the floor sensor is detecting the second state, the lowering step is executed, and if the floor sensor is not detecting the second state, the dump lowering step is executed. It is a feature of.

  According to the first feature of the present invention, a single up switch having a switch function for dumping operation and a switch function for loading operation is provided, and the up switch, when the up switch is operated to the up operation position, has a loading platform. If the forward limit sensor is detecting a state where the is in the forward limit with respect to the swing frame, the dumping step is executed, and if not, the loading step is executed. With this, the dumping operation switch function and the loading operation switch function are automatically operated according to the forward position of the platform (that is, whether it is the forward limit or not) by simply operating and inputting one up switch to the up operation position. Since it is selectively exerted, the switch structure and the wiring can be simplified accordingly, which can contribute to cost reduction and enhance the operability.

  Further, according to the second feature, a single down switch having a dump truck lowering operation switch function and a lowering operation switch function is provided, and the down switch, when operated to the down operation position, swings. If the landing sensor is detecting the state where the moving frame is lying down on the vehicle body, the lowering step is executed, and if not, the dump lowering step is executed. As a result, by simply inputting one down switch to the down operation position, the lowering operation switch function and the dump lowering operation switch function can be obtained according to the tilt position of the swing frame (that is, whether or not it is in the floor). Is automatically and selectively exerted, the switch structure and the wiring can be simplified accordingly, which can contribute to cost reduction, and the operability can be enhanced.

  Further, according to a third feature, a single up / down switch having the functions of the above-mentioned up switch and down switch is provided, and the up / down switch is the same as the first feature when the up / down switch is operated to the up operation position. The function of the up switch is exerted, and the function of the down switch according to the second feature is exerted when operated to the down operation position. As a result, simply by operating and inputting one up / down switch to the up operation position, the dump lifting operation switch function and the loading operation switch function are automatically and selectively exhibited according to the forward position of the platform. , By simply inputting the operation of the up-down switch to the down operation position, the unloading operation switch function and the dump lowering operation switch function are automatically and selectively exerted according to the tilt position of the swing frame. The switch structure and the wiring can be simplified, which can contribute to further cost reduction and also improve the operability.

Overall side view showing a transport vehicle according to a first embodiment of the present invention Side view of main parts of the transport vehicle 2A and 2B show a swing frame and a guide frame of the transportation vehicle, where FIG. 3A is a view taken along arrow 3A in FIG. 2, FIG. 3B is a view taken along arrow 3B in FIG. 2, and FIG. View It shows the relative positions of the swing frame, the vehicle body, the platform, etc. of the transport vehicle, (A) is an enlarged sectional view taken along line 4A-4A of FIG. 1, and (B) is an enlarged sectional view taken along line 4B-4B of FIG. The figure and (C) are 4C-4C line enlarged sectional views of FIG. The relational positions of the swing frame, the guide frame, the vehicle body, the cargo bed, etc. of the transportation vehicle are shown, (D) is an enlarged sectional view taken along line 5D-5D in FIG. 1, and (E) is 5E-5E in FIG. Line enlarged sectional view, (F) is an enlarged sectional view taken along line 5F-5F in FIG. 1, and (G) is an enlarged sectional view taken along line 5G-5G in FIG. 6-6 line enlarged sectional view of FIG. Front view of essential parts showing an example of the operation panel of the driver's seat Circuit diagram showing an example of a hydraulic circuit Block diagram showing an example of a control block diagram of the hydraulic control device It is a side view showing an example of a dumping process, and a solid line shows a state where a loading platform is in the most standing posture. It is a side view which shows an example of a loading platform unloading process, (A) shows the state just after starting unloading, (B) shows the state in the middle of unloading, (C) shows the unloading completion state, respectively. Flowchart 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 Flowchart showing an example of control of the loading process Flowchart showing an example of an output procedure of a dump up command or a loading command according to an operation input to the up switch and an output procedure of a dump lowering command or an unloading command according to an operation input to the down switch The principal part front view which shows an example of the operation panel of the driver's seat in the transport vehicle which concerns on 2nd Embodiment of this invention (FIG. 7 corresponding figure).

  First, an example of a transportation vehicle according to the present invention will be described with reference to FIGS. The transport vehicle T of the first embodiment is used both 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 this 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 made of a metal frame frame, a cabin 1 arranged at the front of the vehicle body F, and a loading platform 3 mounted on the vehicle body F behind the cabin 1 via a swing frame 2. With. The structure of the rocking 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 with an open upper surface, and has a rectangular bottom plate portion 31, a front plate portion 32 standing upright from the front edge and left and right side edges of the bottom plate portion 31, and the left and right sides. The side plates 33 and 34 and the rear door 35 that can open and close the rear end opening of the luggage 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 provided 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-shaped cross section open to the L side).

  Further, the lower end portions of the left and right side plate portions 33, 34 are pivotally supported around the left and right side edge portions of the bottom plate portion 31 around the front-rear axis in the present embodiment, and the upright state thereof is the left and right side plate portions 33, 34 and the front plate portion. It is held by a clamp mechanism (not shown) that detachably couples the 32. If the connection by the clamp mechanism is released at any time, the left and right side plate portions 33, 34 are swung downward around the pivotal support portion at the lower end of the left and right side plate portions 33, 34, as shown by the chain double-dashed line in FIG. The side can be opened. The left and right side plate portions 33, 34 may have their lower ends fixed to the bottom plate portion 31.

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

  In the first switching mode, when the transport vehicle T is used as, for example, a construction machine transport vehicle, when the loading platform 3 is at the final retracted position 3R (see, for example, FIG. 11C) described later, the above-mentioned construction on the ground is performed. This is selected when the rear door 35 functions as a connecting plate for smoothly loading the machine K onto the platform 3. On the other hand, the second switching mode is selected when the transport vehicle T is used as a dump truck, and the selection causes the rear door 35 opened by the dumping operation (see FIG. 10) of the cargo bed 3 to pass from the rear end of the cargo bed 3 to the earth and sand. It is possible to smoothly discharge the load such as.

  The swing frame 2 is fixed to the swing frame main body 20, a pair of left and right guide rails 21 fixed to the swing frame main body 20 and extending in the front-rear direction, and fixed to the rear portion of the swing frame main body 20 and extends rearward. And a pair of left and right hinge frames 22. The swing frame 2 has its rear end portion (that is, the hinge frame 22) pivotally supported by the rear end portion of the vehicle body F via the first pivot P1. The loading platform 3) oscillates between an upright posture (refer to the solid line in FIG. 10) inclined rearward and downward about the first axis P1 and a substantially horizontal reclining posture (refer to the solid line in FIG. 1 and the chain line in FIG. 10). It is possible to move.

  The oscillating frame main body 20 has a structure in which a plurality of metal frame members are framed vertically and horizontally in a ladder shape and is formed in a substantially rectangular shape that is long in the front-rear direction. Specifically, it is mounted and supported on a seating frame Fc) fixedly mounted on the vehicle body F so as to be able to come into contact with and separate from it. Further, the lower end surface of the lower surface of the loading platform 3 (more specifically, the lower frame 31b described above) is placed and supported on the upper surfaces of the left and right side edge portions of the swing frame main body 20 so that they can come into contact with and separate from each other.

  The pair of left and right guide rails 21 are formed inwardly open in a U-shaped cross section, and a pair of left and right support brackets 31a extending downward from the front part of the bottom surface of the loading platform 3 are provided in the guide rails 21. The guide wheels 36 that are rotatably supported are engaged so as to be rollable in the front-rear direction. The guide rail 21 has an inclined guide portion 21a inclined rearward and upward by a predetermined length 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.

  A hoisting device Ac for hoisting and rocking the rocking frame 2 together with the luggage carrier 3 is interposed between the rocking frame 2 and the vehicle body F. The hoisting device Ac includes a link mechanism 23 including a pair of links 23a and 23b, one end of which is pivotally connected to the intermediate portion of the swing frame 2 and the vehicle body F, and the other end of which is pivotally supported so as to be bendable. An undulating cylinder Cc is provided between one link 23a and the vehicle body F. When the hoisting cylinder Cc extends, the rocking frame 2 rises and rocks together with the cargo bed 3 (that is, dumping operation), and when the cylinder Cc contracts, the rocking frame 2 tilts down together with the cargo bed 3 (that is, dumps down). Operate.

  A front portion of the guide frame 4 is connected to a rear portion of the swing frame 2 (a rear end portion of the guide rail 21 in the embodiment) so as to be vertically swingable around the second pivot line P2. The guide frame 4 includes left and right side frame parts 40s having an L-shape in a side view and a rear frame part 40r that connects between rear end parts (especially, upper and lower intermediate parts) of the left and right side frame parts 40s in a plan view. It is formed in a U shape. Front and rear guide wheels 41, 42 are rotatably supported by the guide frame 4 (more specifically, the portions extending in the front-rear direction of the left and right frame portions 40s) so as to be spaced apart in the front-rear direction. The rear guide wheels 41 and 42 engage with the lower frame 31b of the luggage carrier 3 so as to be rollable in the front-rear direction.

  Further, a slide cylinder Cs for moving the platform 3 back and forth with respect to the swing frame 2 is interposed between the swing frame 2 and the platform 3. The rear end portion of the piston rod of the slide cylinder Cs is pivotally connected to the rear end portion of the lower surface of the loading platform 3 so as to be rotatable about a third pivot line P3, and 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 slide cylinder Cs alone is used to extend and retract the loading platform 3 to a predetermined rearward tilting position 3R (see FIG. 11C) at which the ground construction machine K can ride on the loading platform 3. It is possible to drive between the most forwardly mounted position 3F (see the solid line in FIG. 1 and the chain line in FIG. 10) where the loading platform 3 is mounted substantially horizontally on the swing frame 2 that is lying down on the vehicle body F. In that case, the guide rail 21 cooperates with the guide frame 4 to tilt the load platform 3 backward so as to gradually increase the tilt angle as the load platform 3 approaches the final retracted tilt position 3R in the latter half of the lowering process of the load platform 3. Can be made).

  Further, the rear portion of the guide frame 4 can be expanded and contracted between the extended state in which the loading platform 3 can be grounded when the loading platform 3 is in the rearmost retracted position 3R and the retracted state retracted upward from the extended state (that is, the posture). (Changeable) jack J is provided. In the following description, the operation of the jack cylinder Cj is called an extension operation for the extension operation for changing the posture of the jack J from the retracted state to the extended state, and the posture change from the extended state to the retracted state is performed. The storage operation for is sometimes called 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 cross section and a pair of left and right movable frames 62 that are fitted and supported in the fixed frame 61 so as to be vertically slidable. The auxiliary wheel 63 rotatably supported on the lower end of each movable frame 62, the 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 therein. The storage sensor J-LS includes 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 in the ascending limit).

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

  The fixed frame 61 has a pair of left and right, and is fixed to the inner surfaces of the left and right frame portions 40s (more specifically, the rear end portion having a trapezoidal plate shape that is long in the vertical direction) of the swing frame 2. Further, in the jack cylinder Cj, the cylinder barrel is fixed to the left and right intermediate portions of the rear frame portion 40r of the guide frame 4, and the lower end of the piston rod is pivotally connected to the horizontal connecting member 64 that connects the lower end portions of the left and right movable frames 62 to each other. Are 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 being lifted up from the vehicle body F in a state where the loading platform 3 is retracted from the forward limit of the rocking frame 2. A lifting prevention mechanism 50 is provided which releases the engagement in association with the luggage carrier 3 when the luggage carrier 3 is in 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 pivotal support 51p that allows the upper and lower intermediate portions of the swinging frame body 20 to swing back and forth, so that the vehicle body F (specifically, Between the lock position (see the chain line in FIG. 1 and the solid lines in FIG. 11) and the lock release position in which the lock is not possible (see the solid lines in FIGS. 1 and 10). A movable lock member 51, a lock spring 52 as a biasing means for constantly biasing the lock member 51 toward the lock position side (that is, clockwise in FIG. 1), and a lock member 51 fixed to the loading platform 3 And an unlocking member 53 that can be engaged and disengaged. The lock releasing member 53 is engaged with the lock member 51 so as to move and hold the lock member 51 in the lock releasing position in association with the forward movement of the platform 3 from the position immediately before the forward limit to the swing frame 2 to the forward limit. To do.

  When the lock member 51 is separated from and released from the lock release member 53, the lock member 51 is biased by the lock spring 52 and is held at the lock position to be locked to the vehicle body F (locking pin 54). This makes it possible to prevent the swing frame 2 from rising from the vehicle body F. Further, the locking member 51 rotates counterclockwise to the unlocked position against the lock spring 52 in conjunction with the loading platform 3 approaching and reaching the forward limit, thereby swinging through the locking member 51. The locked state between the frame 2 and the vehicle body F is released. Due to this unlocking, there is no possibility that the lifting prevention mechanism 50 will become an obstacle when the rocking frame 2 undulates and rocks together with the cargo bed 3 in the later-described dumping up / down process of the cargo bed 3.

  A forward limit sensor S-LS including a limit switch (for example, a proximity switch) capable of detecting a state where the platform 3 is in the forward limit with respect to the swing frame 2 is provided between the platform 3 and the swing frame 2. The forward limit sensor S-LS is, for example, a sensor main 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 platform 3 (that is, the lower frame 31b). , And the dog piece 71d fixed to the other one of them. Then, the dog piece 71d closely faces the sensor main body 71s when the loading platform 3 is at the forward limit of the rocking frame 2 or in the vicinity thereof, whereby the sensor main body 71s is in a detection (that is, on) state.

  Further, between the swing frame 2 and the vehicle body F, there is provided a landing sensor F-LS capable of detecting that the swing frame 2 is lying down on the vehicle body F. This landing sensor F-LS includes, for example, a sensor main body 72s including a detection element fixed to one of the vehicle body F (seating frame Fc) and the swing frame 2 (that is, the side frame portion of the swing frame body 20), It has a dog piece 72d fixed to the other one. Then, the dog piece 72d closely faces the sensor main body 72s in a state where the swing frame 2 is laid down on the vehicle body F (sitting frame Fc), whereby the sensor main body 72s is in a detection (that is, 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. These switches include a power switch P-SW, a power take-out switch PTO-SW, and an ON switch. A dumping operation for swinging the platform 3 together with the swing frame 2 in the upright direction when operated, or driving the platform 3 from the last backward tilting position 3R to the most forward loading position 3F (that is, the loading process is executed). Up switch U-SW for carrying out a loading operation for carrying out, and a dumping lowering operation for rocking the loading platform 3 together with the rocking frame 2 in the laid-down direction by being turned on, or moving the loading platform 3 forward most. At least a down switch D-SW for performing a lowering operation for driving (that is, performing a lowering step) from the mounting position 3F to the final retracted position 3R is included.

  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 the power take-out device (PTO) mounted on the vehicle at any time to be in the power-connected state and power-off state. This is for selectively switching to the state, and in the power connection state, the output of the vehicle-mounted engine is transmitted to the hydraulic pump PO described later, so that the hydraulic pump PO is driven.

  In the present embodiment, the up switch U-SW and the down switch D-SW are 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. However, it may be configured by an alternate switch capable of selectively fixing the ON operation and the OFF operation.

  Further, the operation panel 10 is provided with an error display means 11 (for example, a display lamp group) for notifying an operator of an abnormality during the process execution (that is, an error display). The display mode of the error display means 11 is preferably such that it is possible to easily distinguish the error state in the initial stage of startup from the error state during the process, for example, by the difference in color or blinking. It is desirable that the display mode be capable of identifying whether the error state is caused by the failure of -LS, S-LS, or J-LS.

  In the present embodiment, the error 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 dumping, lowering, lowering, and loading steps described later. , S26, S27, S29, S45, S56, S65, S81, S82.

  Further, instead of or in addition to the error display means 11, the operation panel 10 is used to notify an operator of an abnormality during the process execution or to alert the operator regarding a specific operation (for example, a storing operation of the jack J). A warning sound generating means 12 (for example, a warning buzzer, a speaker, etc.) is provided. It is desirable that the alarm sound from the alarm sound generating means 12 can easily identify the content and degree of the abnormality from the tone color, volume, etc. of the alarm sound, or in place of or in addition to the simple alarm sound, an error state. You may make it emit the message sound explaining.

  By the way, FIG. 8 shows an example of a hydraulic circuit HC that controls the supply and discharge of the operating hydraulic pressure to the undulating cylinder Cc and the slide cylinder Cs. Then, 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, U-SW, D-SW, and various sensors F-. The electronic control unit EC connected to the LS, S-LS, and J-LS constitutes the hydraulic control unit C of the present invention.

  The hydraulic circuit HC includes a hydraulic pump PO that sucks and pressure-feeds the oil in the oil tank TA, and a first electromagnetic unit SOL1 for selecting the dumping that guides the discharge side of the hydraulic pump PO to the extension oil chamber 100 of the undulating cylinder Cc. And a first control valve V1 having a second electromagnetic portion SOL2 for jack contraction selection that guides the discharge side to the contraction oil chamber 101 of the jack cylinder Cj, and the extension oil chamber 100 of the undulating cylinder Cc to the oil tank TA. A normally-closed second control valve V2 having a third electromagnetic portion SOL3 for selecting a dump lowering for connecting the return oil passage, and the extension oil chambers 102 of the jack cylinder Cj and the slide cylinder Cs on the discharge side of the hydraulic pump PO. , 103 for jack extension / rear slide selection, and fifth solenoid S for front slide selection, which guides to the contraction oil chamber 104 of the slide cylinder Cs. And a third control valve V3 having L5.

  In the oil passage between the third control valve V3 and both oil chambers 103 and 104 of the slide cylinder Cs, the contraction oil chamber 104 of the slide cylinder Cs and the oil tank TA are normally shut off, and the jack cylinder Cj is provided. A counter balance valve Vcb for starting the extension operation of the slide cylinder Cs is provided by opening the valve when the operating oil pressure reaches the extension limit and rises above a predetermined value. That is, the counter balance valve Vcb causes the contraction of the jack J and the forward movement of the loading platform 3 in this order so that the expansion operation of the slide cylinder Cs is started after the expansion of the jack cylinder Cj reaches the expansion limit first. Sequence control with.

  The electronic control unit EC is preset and stored based on the operation input to the up switch U-SW and the down switch D-SW and the detection results of the various sensors F-LS, S-LS, J-LS. The control program controls the electromagnetic parts SOL1 to SOL5 of the control valves V1 to V3 to perform supply / discharge control of operating hydraulic pressure for each cylinder Cc, Cs, Cj (thus, operation control of each cylinder Cc, Cs, Cj). As a result, the transport vehicle T can execute the dumping / lowering process, and the loading / unloading process and loading process of the loading platform 3.

  Next, with reference to FIG. 16, an output procedure of each command for instructing dumping or loading according to an operation input to the up switch U-SW and dump lowering according to an operation input to the down switch D-SW. Or, the output procedure of each command for instructing the unloading will be described. It should be noted that these command output procedures are executed in the electronic control unit EC activated by turning on the power switch P-SW based on a control program incorporated in advance. Each command is output in the electronic control unit EC, for example, in the form of an electric signal (for example, a voltage signal, a current signal, etc.). The output destination of each command is a control unit in the electronic control unit EC (that is, a control unit for executing each step of dumping, lowering, lowering, and loading described later based on a control program).

  First, in step S101, it is determined whether the up switch U-SW is turned on. If it is turned on, the process proceeds to step S102. In step S102, it is determined whether or not the forward limit sensor S-LS detects the state where the platform 3 is in the forward limit with respect to the swing frame 2 (that is, the first state). If the forward limit is in the forward limit, the process proceeds to step S103. Then, a dump raising command (that is, an operation command for executing the dump raising process) is output, and the process returns. When it is determined in step S102 that the loading platform 3 is not in the forward limit (that is, the forward limit sensor S-LS is in the non-detection state), the process proceeds to step S104, and the loading command (that is, the loading step). The operation command for executing is output, and the process returns.

  In this way, the dumping command and the loading command are selected in the detection state of the forward limit sensor S-LS at the time when the up switch U-SW is turned on (that is, whether the loading platform 3 is in the forward limit). Output is possible. For example, if the loading platform 3 is in the forward limit at the time when the up switch U-SW is turned on, it is estimated that the loading is completed. Therefore, the dump lifting command is selectively output to safely perform the dump lifting process. It is feasible. On the other hand, if the loading platform 3 is not in the forward limit at the time when the up switch U-SW is turned on, the loading is inferred to be incomplete, so the loading process is executed by selectively outputting the loading command. It

  When it is determined in step S101 that the up switch U-SW is not turned on, the process proceeds to step S105, it is determined whether the down switch D-SW is turned on, and it is not turned on. Will be a return to. When it is determined in step S105 that the down switch D-SW has been turned on, the process proceeds to step S106, and the rocking frame 2 is placed on the vehicle body F in a landing state (second state). It is determined whether the floor sensor F-LS is detecting. If it is in the landing state, the process proceeds to step S107 to output a unloading command (that is, an operation command for executing the unloading process) and return. If it is determined in step S106 that the swing frame 2 is not in the landing state on the vehicle body F (that is, the landing sensor F-LS is in the non-detection state), the process proceeds to step S108 to dump the vehicle. A lowering command (that is, an operation command for executing the dump lowering step) is output, and the process returns.

  In this way, when the down switch D-SW is turned on, when the landing sensor F-LS detects the state (that is, whether the swing frame 2 is in the landing state on the vehicle body), the lowering command and the dump command are given. It is possible to selectively output the down command and. For example, if the swing frame 2 is in the landing state when the down switch D-SW is turned on, it is presumed that the dump lowering is completed. Therefore, the lowering command is selectively output, so that the lowering process can be performed safely. Is feasible. On the other hand, if the swing frame 2 is not in the landing state at the time of the ON operation of the down switch D-SW, it is estimated that the dump lowering is incomplete, so that the dump lowering command is selectively output to output the dump lowering step. Is executed.

Next, the basic operations of the dumping up / down process controlled by the hydraulic control device C, and the loading / unloading process and loading process of the platform 3 will be sequentially described. Each step is performed in a state where the power switch P-SW is turned on and the power take-out switch PTO-SW is in the PTO connection state. In this state, the up switch U-SW and the down switch D-SW are Is not operated (thus, none of the above-mentioned dump raising command, loading command, unloading command, and dump lowering command is output), the electromagnetic units SOL1 to SOL5 of the control valves V1 to V3 are not operated. In the excited state, each process is in the standby state.
[Basic operation of dumping process]
When the dump raising command is output based on the ON operation of the up switch U-SW, the first electromagnetic portion SOL1 of the first control valve V1 is excited, so that the discharge side of the hydraulic pump PO has an oil chamber for extension of the undulating cylinder Cc. Connect to 100. As a result, the hoisting cylinder Cc extends, and in conjunction with this, the swing frame 2 (hence, the loading platform 3) swings in the upright direction, that is, the dumping operation, as shown in FIG. The substance flows down from the rear end under its own weight and is discharged.

Further, when the dump raising command is not output during the dump raising (that is, the worker releases the up switch U-SW), the first control valve V1 returns to the neutral position, so that the undulating cylinder Cc stops extending. Then, the swing frame 2 (hence, the loading platform 3) stops at the raising position at that time.
[Basic operation of dump lowering process]
When the dump lowering command is output based on the ON operation of the down switch D-SW in the above-described dump raising state, the electromagnetic portion SOL3 of the second control valve V2 is excited to cause the extension oil chamber 100 of the undulating cylinder Cc. Communicates with the oil tank TA. As a result, the hoisting cylinder Cc on which the weight of the load platform 3 acts contracts, and the swing frame 2 (and therefore the load platform 3) swings in the inclining direction, that is, the dump lowering action, and finally as shown in FIG. Then, stop in a horizontal lying position on the body F.

Further, when the dump lowering command is not output during the dump lowering (that is, the worker releases his / her hand from the down switch D-SW), the second control valve V2 returns to the neutral position for extending the undulating cylinder Cc. The oil chamber 100 and the oil tank TA are shut off from each other. As a result, the contraction operation of the undulating cylinder Cc is stopped, and the swing frame 2 (and thus the platform 3) is stopped at the lowered position at that time.
[Basic operation of the unloading process]
When the lowering command is output based on the ON operation of the down switch D-SW, the fourth solenoid SOL4 of the third control valve V3 is excited to cause the discharge side of the hydraulic pump PO to move to the slide cylinder Cc and the jack cylinder Cj. It communicates with the extension oil chambers 103 and 102. At this time, due to the action of the counter balance valve V4 described above, the jack cylinder Cj is first extended, and the extension of the slide cylinder Cs is started after reaching the extension limit.

  During this period, as the slide cylinder Cs extends, the luggage carrier 3 moves rearward along the swing frame 2 (guide rail 21) and the guide frame 4 as shown in FIGS. 11 (A) and 11 (B). Especially, the front part of the loading platform 3 is slightly lifted due to the front tilting form of the guide rail 21 and the rearward tilting swing of the guide frame 4. Then, with the subsequent backward movement of the platform 3, the trailing downward angle of the platform 3 gradually increases as the guide wheel 36 in the front part of the platform 3 approaches the second axis P2, and finally, as shown in FIG. As shown, the slide cylinder Cs stops extending at the final retracted position 3R in which the rear end of the loading platform 3 comes into contact with the ground.

In this state, the rear door 35 of the luggage carrier 3 is swung backward around the lower hinge connecting portion to form a crossing board as shown in FIG. 11C, and the construction machine K (object to be transported) can be loaded on the luggage carrier 3.
[Basic operation of loading process]
When the loading command is output based on the ON operation of the up switch U-SW, the fifth electromagnetic portion SOL5 of the third control valve V3 is excited, so that the discharge side of the hydraulic pump PO receives oil for contracting the slide cylinder Cc. It communicates with the chamber 104. As a result, the bed 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. By the cooperation, the posture gradually changes to a horizontal posture (that is, changes as shown in FIG. 11 (C) → (B) → (A) → FIG. 1). Then, when the loading platform 3 finally reaches the limit of forward movement with respect to the swing frame 2, the slide cylinder Cs contracts and stops at the most forward movement mounting position 3F.

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

Next, description will be made with reference to the flowcharts of FIGS. 12 to 16 showing an example of the control procedure of each step described above. In the flow chart of each process, the electronic control unit EC is operated with the power switch P-SW being turned on to energize the electronic control unit EC and the power take-off switch PTO-SW to bring the power take-out unit to the power connection state. It is executed based on a control program for storage.
[Example of control of dumping process]
In FIG. 12, when the dump-up command is output based on the ON operation of the up switch U-SW in step S1, the process proceeds to step S2, it is determined whether the down switch D-SW is in operation, and if the down switch D-SW is in operation. Goes to step S3 to enter an all-stop state in which all the cylinders Cc, Cs, Cj make an emergency stop, and returns to the standby state again. Here, the emergency stop refers to a state in which expansion / contraction of all the cylinders Cc, Cs, Cj is stopped. In this embodiment, all the electromagnetic parts SOL1 to SOL5 are de-excited so that the discharge side of the pump Po is a cylinder. It refers to a state in which it does not communicate with any of the oil chambers Cc, Cs, Cj, and therefore all cylinders Cc, Cs, Cj do not expand and contract. It should be noted that all cylinders Cc, Cs, Cj may be prevented from expanding and contracting by blocking the discharge of oil from each oil chamber to the tank T.

  When it is determined in step S2 that the down switch D-SW is not being operated, the process proceeds to step S4, in which the start determination is made, that is, both the storage sensor J-LS and the forward limit sensor F-LS are on (that is, the jack J is It is determined whether the storage state is the forward direction of the loading platform 3). If neither is on, the process proceeds to step S5, an error message is displayed, the dumping process is not started, and the process is in a standby state.

  If both sensors J-LS and F-LS are both turned on in step S4, the process proceeds to step S6 to excite the first electromagnetic portion SOL1 of the first control valve V1, and thereby the undulating cylinder Cc extends. Since the working hydraulic pressure is supplied, the swinging of the platform 3 in the upright 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 loading platform 3 is displaced rearward. If both of them remain on, the process proceeds to step S8, and it is determined again whether the dump raising command is being output. If the dumping command is being output, the process returns to step S7, and if it is not being output, the process proceeds to step S9. In step S9, the first electromagnetic unit SOL1 excited in step S6 is de-excited, so that the extension of the undulating cylinder Cc is stopped and the dumping operation is stopped.

When both the sensors J-LS and F-LS are no longer turned on in step S7, the process proceeds to step S10, an error message is displayed, and further the process proceeds to step S9 to stop the dump lifting operation, whereby the dump lifting process is performed. It becomes a standby state.
[Damp lowering process control example]
In FIG. 13, when the dump lowering command is output based on the ON operation of the down switch D-SW in step S11, the process proceeds to step S12, it is determined whether the up switch U-SW is in operation, and if it is in operation, Proceeding to step S13, all cylinders Cc, Cs, Cj are brought into an all-stop state in which they are urgently stopped, and then return to the standby state again.

  When it is determined in step S12 that the up switch U-SW is not being operated, the process proceeds to step S14, in which it is determined whether or not the start sensor is in the storage sensor J-LS (that is, the jack J is in the storage state). . If it is not turned on, the process proceeds to step S15, an error message is displayed, the dump lowering process is not started, and a standby state is set.

  When the storage sensor J-LS is turned on in step S14, the process proceeds to step S16, and the hydraulic oil for advancing the loading platform 3 to the slide cylinder Cs by exciting the fifth electromagnetic portion SOL5 of the third control valve V3 is used. (That is, contraction hydraulic pressure) is started to be supplied, whereby the slide cylinder Cs is urged in the contraction direction (that is, the loading platform 3 in the forward direction). Next, in step S17, it is determined whether 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 or not the forward limit sensor S-LS is ON (that is, the load platform 3 is in the forward limit with respect to the swing frame 2). If it is not ON, the process proceeds to step S28, and if it is ON, the process proceeds to step S19. .

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

  Further, in step S21, the oil chamber 100 for extension of the undulating cylinder Cc communicates with the oil tank TA by the excitation of the third electromagnetic portion SOL3 of the second control valve V2, and the undulating cylinder Cc contracts due to the weight of the loading platform 3. The swinging motion of the loading platform 3 in the down direction, that is, the dump lowering operation is started.

  Next, in step S22, it is determined whether the storage sensor J-LS is on. If it is on, the process proceeds to step S23. In this step S23, it is determined whether the dump lowering command is being output. If it is being output, the process returns to step S22 to continue the dump lowering operation, and if it is not being output, the process proceeds to step S24. In step S24, the third electromagnetic portion SOL3 excited in step S21 is de-excited, so that the extension oil chamber 100 of the undulating cylinder Cc is disconnected from the oil tank TA, and the dump lowering is completed. It should be noted that even if the dump lowering command is output, the dump lowering is completed when the loading platform 3 falls down, and in this case, the output hydraulic pressure from the hydraulic pump PO is relieved 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, similarly to step S20, the slide cylinder Cs stops contracting to stop the forward movement of the loading platform 3, and 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 the process returns to step S24 to put the dump lowering process in a standby state.

In step S28, the elapsed time from the excitation of the fifth electromagnetic unit SOL5 (that is, the forward movement of the loading platform 3 is started) in step S16 is sufficiently long (that is, the forward limit sensor S-LS is estimated to be in failure). It is determined whether a predetermined (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 the process proceeds to step S20. Therefore, even when the forward limit sensor S-LS is still off due to a failure, the process of steps S20 to S24 is executed without any trouble until the failure determination time T2 elapses, and the dump lowering step is performed. It is possible to finish.
[Example of unloading process control]
In FIG. 14, when the down command is output based on the ON operation of the down switch D-SW in step S41, the process proceeds to step S42, and it is determined whether the up switch U-SW is in operation. Proceeding to S43, all the cylinders Cc, Cs, Cj are brought into an all-stop state in which an emergency stop is performed, and the state returns to the standby state again.

  If it is determined in step S42 that the up switch U-SW is not being operated, the process proceeds to step S44, in which it is determined that the engine is starting, that is, the landing sensor F-LS is on (that is, the swing frame 2 is in the landing state on the vehicle body F). In step S45, an error message is displayed and the unloading process is not started, but the standby state is entered.

  When it is determined in step S44 that the landing sensor F-LS is on, the process proceeds to step S46, in which the extension oil chamber 100 of the undulating cylinder Cc is excited by the excitation of the third electromagnetic portion SOL3 of the second control valve V2. Is in communication with the oil tank TA. As a result, the undulating cylinder Cc is urged in the contracting direction by the weight of the loading platform 3, so that the loading platform 3 is always biased and held in the lying posture on the vehicle body F during the unloading process. Note that this state is referred to as "dump reduction" in step S46 of FIG.

  Next, in step S47, it is determined whether the forward limit sensor S-LS is on (that is, the loading platform 3 is in the forward limit with respect to the swing frame 2), and if it is on, the process proceeds to step S48.

  In this step S48, the hydraulic oil (that is, the hydraulic pressure for contraction) for advancing the platform 3 is started to be supplied to the slide cylinder Cs by the excitation of the fifth electromagnetic portion SOL5 of the third control valve V3, and at this time as well. If the platform 3 is slightly behind the regular forward limit (in this case, the forward limit sensor F-LS is on, that is, the detection range has some width), the platform 3 moves forward to the regular forward limit. Moving. Next, the process proceeds to step S49, and the elapsed time from the excitation of the fifth electromagnetic unit SOL5 in step S48 (that is, from the start of the forward movement of the loading platform 3) has passed a predetermined preliminary advance time T3 (for example, 0.5 seconds). 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-excited, the supply of the contracting hydraulic pressure to the slide cylinder Cs is stopped, and the forward movement of the platform 3 is stopped.

  Further, 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 the excitation of the fourth electromagnetic portion SOL4 of the third control valve V3. In this case, by the action of the counter balance valve V4, the extension operation of the jack cylinder Cj and the extension operation of the slide cylinder Cs (that is, the rearward movement of the bed 3) are sequence-controlled in this order, and finally the slide cylinder Cs is operated. The extension of the slide cylinder Cs is stopped depending on whether the extension limit is reached or the load platform 3 is in contact with the ground, and at this time, the load platform 3 is in the final retracted position 3R.

  During the sequence control, steps S52 and S53 are executed. That is, in step S52, 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 (landing state), the process proceeds to step S53. It is determined whether the unload command is being output. If the lowering command is being output, the process returns to step S52, and if it is not being output, 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 is stopped.

  Next, in step S55, the third electromagnetic portion SOL3 of the second control valve V2, which is excited in step S46, is de-energized, so that the extension oil chamber 100 of the undulating cylinder Cc is shut off from the oil tank TA, that is, " The "Dump dump" status is released.

If it is determined in step S52 that the landing sensor F-LS is not on (that is, the rocking frame 2 is in the landing state), the process proceeds to step S56, an error message is displayed, and the process returns, so the unloading process (hence, The operation of each cylinder Cc, Cs, Cj) is in a standby state.
[Example of control of loading process]
In FIG. 15, when the loading command is output based on the ON operation of the up switch U-SW in step S61, the process proceeds to step S62, it is determined whether the down switch D-SW is in operation, and if it is in operation, Proceeding to step S63, all the cylinders Cc, Cs, Cj are brought into an all-stop state in which an emergency stop is performed, and the state returns to the standby state again.

  Further, when it is determined in step S62 that the down switch D-SW is not being operated, the process proceeds to step S64, in which it is determined whether or not to start, that is, the landing sensor F-LS is turned on (that is, the swing frame 2 is in the landing state on the vehicle body F). ). If it is not on, the process proceeds to step S65, an error message is displayed, the loading process is not started, and the process is in 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. Then, in step S66, the extension oil chamber 100 of the undulating cylinder Cc is brought into communication with the oil tank TA due to the excitation of the third electromagnetic portion SOL3 of the second control valve V2. Since the loading platform 3 is biased in the contracting direction, the loading platform 3 is constantly biased and held in the lying posture on the vehicle body F during the loading process. Note that this state is referred to as “dump reduction” in step S66 of FIG. 15, as in step S46 described above.

  Further, in step S67, the hydraulic oil (that is, the hydraulic pressure for contraction) for advancing the bed 3 is started to be supplied to the slide cylinder Cs by the excitation of the fifth electromagnetic portion SOL5 of the third control valve V3. It moves forward with respect to the swing frame 2. Next, in step S68, it is determined whether the landing sensor F-LS is on (that is, the swing frame 2 is in the landing state), and if it is on, the process proceeds to step S69. In this step S69, it is determined whether or not the loading command is being output, and if not being output, the process proceeds to step S83 described later, but if it is being output, the process proceeds to step S70, and the forward limit sensor S-LS is turned on (that is, the loading platform). 3 is a forward limit with respect to the swing frame 2).

  Then, in step S70, when the forward limit sensor S-LS is turned on (that is, the loading platform 3 is in the forward limit), the process proceeds to step S71, and the elapsed time from turning on the forward limit sensor S-LS is a predetermined extended forward time T4. It is determined whether (for example, 1 second) has elapsed, and if it has elapsed, the process proceeds to step S73 via step S72. Then, in step S72, the fifth electromagnetic portion SOL5 excited in step S67 is de-excited, the supply of the contraction hydraulic pressure to the slide cylinder Cs is stopped, and the forward movement of the luggage carrier 3 is stopped at the forward limit.

  If it is determined in step S70 that the forward travel limit sensor S-LS is not on (that is, the loading platform 3 is not running forward), the process proceeds to step S74, in which the fifth electromagnetic unit SOL5 is excited (that is, the loading platform 3 moves forward). It is determined whether a predetermined failure determination time T2 (for example, 20 seconds) has elapsed after the start of the forward movement is sufficiently long (that is, long enough to infer that the forward limit sensor S-LS is in failure), and the elapsed time is determined. If not, the process returns to step S68, and if it is determined that the time has passed, the process proceeds to step S72. As a result, even when the forward limit sensor S-LS remains off due to a failure, it is possible to wait for the failure determination time T2 and perform the processing in steps S73 to 80 described below, which may be an obstacle until the end of the storage of the jack J. It becomes possible to carry out the loading process to the end.

  Then, in step S73, the contracting hydraulic pressure is supplied to the jack cylinder Cj by the excitation of the second electromagnetic portion SOL2 of the first control valve V1, the jack J contracts, and the alarm sound generating means 12 such as a buzzer sounds an alarm. To alert the workers. Next, in step S75, 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 passed a predetermined end determination time T5 (for example, 10 seconds), and if it has not elapsed, the process proceeds to step S77. In this step S77, it is judged whether or not the storage sensor J-LS is turned on (that is, the jack cylinder Cj is in the contraction limit). If it is not turned on, the process returns to step S75, and if it is turned on, the process proceeds to step S78. In step S78, it is determined whether the elapsed time after the storage sensor J-LS is turned on (that is, the jack cylinder Cj is in the contraction limit) has exceeded a predetermined extended storage time T6 (for example, 0.8 seconds), If so, the process proceeds to step S80 via step S79.

  The end 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). The extended storage time T6 is set shorter than the required storage time of the jack J.

  Then, in step S79, the second electromagnetic portion SOL2 excited in step S73 is de-excited to stop the contraction of the jack cylinder Cj, and the alarm sound generating means 12 also stops the alarm. Further, in step S80, the third electromagnetic portion SOL3 of the second control valve V2 that is excited in step S66 is de-energized, so that the extension oil chamber 100 of the undulating cylinder Cc is shut off from the oil tank TA. The contraction is released.

  Also, when it is determined in step S76 that the elapsed time from the start of 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 contraction and warning of the jack cylinder Cj are issued. The alarm generated 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, an error message is displayed, and then the process proceeds to step S79. The loading process goes into 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, an error message is displayed, and then step S83 is performed to step S80. move on. Then, in step S83, the fifth electromagnetic portion SOL5 excited in step S67 is de-excited, and the contraction operation of the slide cylinder Cs is stopped, so that the loading step also enters the standby state. Note that steps S73 to S80 are continued even if the operation of the up switch U-SW is canceled and the loading command is not output.

  The control examples of the dumping / lowering process, the unloading process, and the loading process of the first embodiment have been described above, but according to the present embodiment, the following special operational effects can be achieved.

  For example, in the dump lowering step shown in FIG. 13 of the present embodiment, when the dump lowering command is output based on the ON operation of the down switch D-SW in the standing state of the load platform 3, the load platform 3 that swings in the lying direction is detected. Before the vehicle falls down on the vehicle body F (particularly before starting dump lowering in step S21 in this embodiment), the hydraulic oil is moved to the slide cylinder Cs for a predetermined preliminary advance time T1 for advancing the platform 3. Is supplied (see steps S16 to S20). As a result, the dump lowering command is output under a situation in which the cargo bed 3 is slightly lowered (that is, the slide cylinder Cs is slightly contracted due to an oil leak or the like) by, for example, leaving the cargo bed 3 in the dumped up state for a long time. Even in such a case, the slide cylinder Cs can be moved forward to the forward limit before the dumping of the loading platform 3 is completed. As a result, it is possible to effectively prevent the loading platform 3 from projecting rearward from the regular mounting position 3F on the vehicle body F in the dump lowering completed state (that is, the traveling posture of the vehicle). Further, it is not necessary for the operator in the driver's seat to get off the vehicle and visually check the presence or absence of the rearward extension of the loading platform 3 each time.

  In the present embodiment, the rocking frame 2 and the vehicle body F are engaged with each other so as to prevent the rocking frame 2 from being lifted up from the vehicle body F in a state where the loading platform 3 is retracted beyond the forward limit of the rocking frame 2. Further, a lifting prevention mechanism 50 that interlocks with the platform 3 to release the engagement when the platform 3 is in the forward limit is provided. Therefore, the lifting of the dumping / lowering function of the loading platform 3 is not impaired, and the floating of the swing frame 2 (and hence the loading platform 3) during the work of loading / unloading the loading platform 3 is mechanically prevented, and the load collapse is also prevented. It is valid. Further, according to the processing of steps S16 to S20, the slide cylinder Cs can be moved forward to the forward limit (and thus the lifting prevention mechanism 50 is disengaged) before the dumping of the loading platform 3 is completed. It is possible to effectively prevent the floating prevention mechanism 50 in the engaged state from interfering with the cargo bed 3 and being damaged when the above is completed.

  By the way, when a large backward force is applied to the loading platform 3 due to sudden acceleration during traveling of the transport vehicle T in which the loading platform 3 and the swing frame 2 are lying down on the vehicle body F, the sliding cylinder Cs in the contracted state is affected. 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 that receives the external force, the slide cylinder Cs slightly expands, and the platform 3 slightly shifts backward relative to the swing frame 2 from the normal forward limit. If the engagement between the rocking frame 2 and the vehicle body F by the lifting prevention mechanism 50 is incomplete in relation to this, there is a possibility of movement, and push-up due to road surface irregularities during traveling in that state. When the cargo bed 3 or the like is vertically vibrated in response to this, the floating prevention mechanism 50 may be solidified in an unengageable state. In this state, it is impossible to prevent the rocking frame 2 (and hence the loading platform 3) from being lifted up while the loading platform 3 is being unloaded / loaded.

  On the other hand, in the unloading process shown in FIG. 14 of the present embodiment, when the unloading command is output based on the ON operation of the down switch D-SW while the loading platform 3 is in the laid-down state, the forward limit sensor S-Ls causes the loading platform 3 to move. If the forward limit of is detected, hydraulic oil is supplied to the slide cylinder Cs for the preliminary advance time T3 to move the platform 3 forward before starting the backward movement of the platform 3 (steps S47 to S50). reference). Therefore, even when the loading platform 3 is slightly displaced rearward from the regular forward limit with respect to the swing frame 2 when the unloading command is output, the loading platform 3 is moved to the regular position before the loading platform 3 is moved backward in step S51. Since the forward movement can be reliably performed up to the forward limit, the lifting prevention mechanism 50 can be reliably reset to the disengaged state. As a result, immediately after that, the lifting prevention mechanism 50 can be reliably switched to the engaged state in conjunction with the backward movement of the loading platform 3, so that the swing frame during the loading / unloading operation of the loading platform 3 can be performed. It is possible to surely prevent the lifting of 2 (hence, the loading platform 3).

  If the forward limit sensor S-Ls is in the non-detection state when the unloading command is output, the cargo bed 3 is moved to a certain extent from the normal forward limit (that is, beyond the detection range of the forward limit sensor S-Ls). It is considered that the floating prevention mechanism 50 located on the side engages the swing frame 2 with the vehicle body F. Here, the case where the forward limit sensor S-Ls becomes the non-detection state when the lowering command is output is, for example, the case where the lowering process is restarted after being temporarily stopped in the middle of the lowering process. In step 50, the swing frame 2 is engaged with the vehicle body F by the steps S47 to S50 at the time of starting the lowering step before the stop. Therefore, it is not necessary to move the loading platform 3 forward as in the case where the forward limit sensor S-Ls is in the detection state. In this case, the work efficiency is increased by performing the shortcut from step S47 to step S51. .

  In addition, in the unloading process of the present embodiment, when the unloading command is output in the laid state of the loading platform 3, the rearward movement of the loading platform 3 is performed in step S51 after the jack J extends from the stored state to the extended state. As started, the extension of the jack cylinder Cj and the extension of the slide cylinder Cs are sequence-controlled in this order. As a result, in the process of lowering the loading platform 3 from the running posture of the vehicle, first, the rearward movement of the loading platform 3 is started after the extension of the jack J is completed. Together with this, work safety is further enhanced.

  Further, in the present embodiment, the hydraulic control device C that controls the supply and discharge of the operating hydraulic pressure to the undulating cylinder Cc causes the undulating cylinder Cc to contract during the lowering process (FIG. 14) and the loading process (FIG. 15) of the platform 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. As a result, even when a large external force acts in the extension direction on the undulating cylinder Cc from the platform 3 via the swing frame 2 due to the movement of the center of gravity of the platform 3, vibration, etc. in the process of lowering or loading the platform 3. The undulating cylinder Cc can be maintained in the contracted state. As a result, the undulating cylinder Cc slightly expands and the swing frame 2 (and therefore the loading platform 3) rises above the upper surface of the vehicle body F, so that the behavior and the posture of the loading platform 3 (and thus the load) are undesired during the unloading or loading process. Stabilization can be effectively prevented in advance.

  Moreover, in the unloading process and the loading process described above, the lifting prevention mechanism 50 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. -It is possible to mechanically prevent the rocking frame 2 (and hence the loading platform 3) from being lifted up during the loading operation. This makes it possible to prevent the lifting of the loading platform 3 (the swing frame 2) more reliably, and for example, the swing frame 2 suddenly lifts up during the operation of unloading / loading, the loading platform 3 vibrates, and the load collapses. It is possible to effectively prevent such situations.

  Further, in the present embodiment, in the loading process (FIG. 15) of driving the loading platform 3 from the rearmost tilting position 3R to the most advanced loading position 3F, the state where the loading platform 3 is at the forward limit in step S70 is set to the forward limit sensor S-Ls. After the detection, the hydraulic oil supply to the slide cylinder Cs for advancing the platform 3 is continued for a while until the predetermined extended forward time T4 elapses, and the supply is performed after the extended forward time T4 elapses. Stop (see steps S71 and S72). As a result, the loading platform 3 can be more reliably positioned at the forward limit at the end of the loading process without being affected by the detection error of the forward traveling limit sensor S-LS. It is possible to effectively prevent unnecessary overhang. Moreover, since the forward limit sensor with high detection accuracy is not required, the cost can be reduced accordingly.

  In addition, even if the loading command is in the non-output state until the extended forward time T4 elapses after the forward limit sensor S-Ls detects that the loading platform 3 is in the forward limit in step S70 described above, the extended forward movement is performed. Until the time T4 elapses, the hydraulic oil supply for advancing the platform 3 is continued (see steps S70 to S72). As a result, the luggage carrier 3 can be more reliably positioned at the forward limit, and it is possible to more effectively prevent the rear end of the luggage carrier 3 from unnecessarily extending when the vehicle is traveling.

  Furthermore, in the present embodiment, during the contraction operation of the jack J in the loading process shown in FIG. 15, the contraction operation of the jack J is performed in response to the storage sensor J-Ls detecting that the jack J is in the retracted state. Although it ends (see steps S73 to S79), in particular, the storage sensor J-Ls indicates that the jack J is in the stored state even after the predetermined end determination time T5 has elapsed since the jack J started the contraction operation. If not detected (that is, YES is determined in step S76), the contraction operation of the jack J is ended by performing a shortcut from step S76 to step S79. As a result, even if the storage sensor J-Ls malfunctions or fails, the contraction operation automatically ends when the end determination time T5 elapses. Therefore, it is determined whether the jack J is in the storage state. It is not necessary for each worker to get off the vehicle one by one and visually check, and work efficiency can be improved.

  In addition, when the storage sensor J-Ls detects that the jack J is in the retracted state during the contraction operation of the jack J in step S73, the predetermined extension storage time T6 elapses from the detection, and The contraction operation is ended (see steps S77 to S79). As a result, even after the storage sensor J-Ls detects the stored state, the contraction operation can be extended continuously for the extended storage time T6 just in case, so that it is less likely to be affected by the detection error of the storage sensor J-Ls. , The jack J can be more reliably placed in the stored state.

  Further, in this embodiment, as is clear from steps S101 to S104 in FIG. 16, a single up switch U-SW having a dumping operation switch function and a loading operation switch function is provided. That is, when the up switch U-SW is operated to the up operation position (on operation position in the embodiment), the state where the platform 3 is in the advance limit with respect to the swing frame 2 (first state) is the advance limit. If the sensor S-LS is detecting, the switch function for dumping operation (that is, the function of outputting a dumping command in response to an operation input to the up operation position) is exerted, and the first state is not detected. In this case, the loading operation switch function (that is, the function of outputting the loading command in response to the operation input to the up operation position) is configured.

  Thus, the dump truck is lifted according to the forward movement position (that is, whether it is in the forward movement limit) of the loading platform 3 by a simple operation input to the up operation position (that is, the ON operation position) of only one up switch U-SW. The operation switch function and the loading operation switch function are automatically and selectively exerted, the switch structure and the wiring are simplified, and the operability is improved.

  Further, in this embodiment, as is clear from steps S105 to S108, a single down switch D-SW having a lowering operation switch function and a dump lowering operation switch function is provided. That is, when the down switch D-SW is operated to the down operation position (the ON operation position in the embodiment), the swing frame 2 is in the landing state (second state) in which the swing frame 2 is laid down on the vehicle body. If the floor sensor F-LS is detecting, the unloading operation switch function (that is, the function of outputting the unloading command in response to the operation input to the down operation position) is exhibited, and if the landing state is not detected. It is configured to exert a dump lowering operation switch function (that is, a function of outputting a dump lowering command in response to an operation input to the down operation position).

  As a result, the mere operation input to the down operation position (that is, the ON operation position) of the single down switch D-SW causes the swing frame 2 to be in the tilted position (that is, the vehicle body F is in the state of being laid down on the floor). Depending on whether or not), the switch function for lowering operation and the switch function for dumping lowering operation are automatically and selectively exerted, which simplifies the switch structure and wiring, and improves operability. .

  Furthermore, in the present embodiment, when one of the up switch U-SW and the down switch D-SW is turned on while the other is turned on, all the cylinders Cc, Cs, Cj are completely stopped. (Eg, steps S1 to S3 in the dumping step, 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). As a result, it is possible to effectively prevent an unexpected situation from occurring in the loading platform 3 or the like due to the simultaneous operation of the up switch U-SW and the down switch D-SW.

  Next, a second embodiment of the present invention will be described with reference to FIG.

  In the above-described first embodiment, each step of dumping or loading is executed by the up switch U-SW, and each step of unloading / dumping is performed by the down switch D-SW. On the other hand, in the second embodiment, instead of the up switch U-SW and the down switch D-SW of the first embodiment, a toggle switch that combines the functions of both switches U-SW and D-SW is used. One up / down switch UD-SW is configured.

  In this case, the up / down switch UD-SW has a down operation position corresponding to the on operation position of the up switch U-SW of the first embodiment (the position indicated by the chain double-dashed line in which the operation knob is tilted upward in FIG. 17) and the down position. A down operation position corresponding to the ON operation position of the switch D-SW (a one-dot chain line position in which the operation knob is tilted downward in FIG. 17) and a neutral position (off position) intermediate between both operation positions are selectively selected. It is configured so that it can be switched to. The up / down switch UD-SW stops only when an operation input is made to the up operation position or the down operation position (that is, the operator puts his / her hand on the operation knob), and becomes neutral when the operator releases the operation knob. It may be configured to be automatically returned to the position, or may be configured to be selectively held at each of the up operation position, the neutral position, and the down operation position.

  According to the second embodiment described above, the single up / down switch UD-SW having the functions of the up switch U-SW and the down switch D-SW of the first embodiment is provided. The -SW exerts the function of the up switch U-SW of the first embodiment when operated to the up operation position (two-dot chain line in FIG. 17), and is operated to the down operation position (one-dot chain line in FIG. 17). At times, the function of the down switch D-SW of the first embodiment is exerted.

  Thus, by simply inputting the operation of one up / down switch UD-SW to the up operation position, the switch function for the dumping operation and the loading operation for the loading operation depending on the forward position of the loading platform 3 (that is, the forward limit or not). The switch function is automatically and selectively exerted, and the up / down switch UD-SW is simply operated to the down operation position to respond to the tilted position of the swing frame 2 (that is, whether or not it is in the landing state). The unloading operation switch function and the dump lowering operation switch function are automatically and selectively exerted, and the switch structure and wiring are further simplified and the operability is further enhanced.

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

  For example, in the above-described embodiment, the construction machine K is exemplified as the transported object to be transported by the transport vehicle T, but the transported object in the present invention is not limited to the construction machine K and may be between the platform 3 and the ground. It includes various types of vehicles capable of self-propelled vehicles (eg, passenger cars, work vehicles, etc.), and vehicles not capable of self-propelled vehicles and various articles (eg, various mechanical devices, containers, assembled houses, etc.).

  Further, in the above-described embodiment, the slide cylinder Cs is independently extended and retracted to move the loading platform 3 to the final retracted position 3R where the ground construction machine K (object to be transported) can get on the loading platform 3 and the vehicle body F in a lying state. The present invention has been applied to a so-called single-action transport vehicle in which the loading platform 3 can be driven between the rocking frame 2 and the most forward mounting position 3F in which the loading platform 3 is mounted substantially horizontally. A so-called double action type transport vehicle (for example, Japanese Utility Model Laid-Open No. 6-18069) in which the cylinder Cc and the slide cylinder Cs cooperate to drive the loading platform 3 between the rearmost tilting position 3R and the most forward mounting position 3F. See) may be applied.

  Moreover, in the said embodiment, although the thing using the single-acting hydraulic cylinder with which the output oil chamber (extension oil chamber 100) was single was shown as the undulating cylinder Cc, it replaces with this and before and behind a piston. A double-acting hydraulic cylinder having two output oil chambers may be used. For example, in the operation of the “dump contraction” executed in steps S46 and S66 of the present embodiment, in the embodiment, the extension oil chamber 100 of the undulating cylinder Cc is communicated with the oil tank TA side (that is, from the extension oil chamber 100 to the oil This is performed by causing oil to flow back to the tank TA, but when the undulating cylinder Cc is of a double-acting type, it is performed by supplying discharge oil from a hydraulic pump to the contracting oil chamber.

  Further, in the above-described embodiment, in the dump lowering step, the dump lowering is started after the predetermined preliminary advance time T1 has passed since the forward limit sensor S-LS was turned on (that is, the forward movement of the loading platform 3 is completed). Although the control example (steps S18 to S21) is performed in this manner, instead of this control example, the dump lowering is started even during the elapse of the preliminary forward movement time T1, and the loading platform 3 falls on the vehicle body F. Another control example in which the preliminary forward movement time T1 elapses (that is, the forward movement of the loading platform 3 is completed) before the dumping lowering stop (step S24) is also possible. Alternatively, instead of the control examples, the forward movement of the loading platform 3 may be started after the start of the dump lowering, and the loading platform 3 may be laid down on the vehicle body F after the elapse of the preliminary forward movement time T1. In this case, A sensor for separately detecting the angle of the bed 3 or the swing frame 2 at which the forward movement should be started is separately provided, and the preliminary advance time T1 has sufficiently passed within the descending time from the angle to the fallen state (that is, the bed 3 (Moving forward is completed).

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

  Further, 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.

  Further, the jack J of the above-described embodiment is exemplified as a jack whose posture can be changed between a splayed state in which it can be grounded and a stored state in which it is retracted above the swelled state by expanding and contracting vertically. The structure of is not limited to the embodiment, and it is sufficient that the posture can be changed at least between the extended state in which grounding is possible and the stored state retracted upward from the extended state. For example, it is also possible to implement a structure in which the posture can be changed between the extended state and the stored state by pivotally supporting the vertically extending arm so that it can swing back and forth or left and right.

  Further, in the above-described embodiment, the jack J has been described as being capable of changing its posture between the extended state and the stored state, but the jack may be fixed to the guide frame 4 (thus, the posture cannot be changed).

  Further, in the above-mentioned embodiment, the posture of the jack J is changed by the actuator (jack cylinder Cj), but it is also possible to implement a structure in which the posture of the jack can be changed manually.

C: Hydraulic control device (control device)
Cc ... ・ Release cylinder Cs ・ ・ ・ ・ ・ ・ Slide cylinder F ・ ・ ・ Vehicle body K ・ ・ ・ Construction machine (transported object)
F-LS ... Floor sensor S-LS ... Forward limit sensor U-SW ... Up switch D-SW ... Down switch UD-SW ... Up-down switch 2 ... Swing frame 3・ ・ ・ ・ ・ Luggage platform 3R ・ ・ ・ Last retracted position 3F ・ ・ ・ ・ Forward most advanced loading position

Claims (3)

A rear end portion of a swing frame (2) extending in the front-rear direction is pivotally supported by a rear portion of the vehicle body (F) so as to be capable of undulating and swinging, and at least a front portion of the luggage carrier (3) is moved forward and backward on the swing frame (2). An undulating cylinder (Cc) that movably engages and oscillates the swing frame (2) together with the loading platform (3) is interposed between the swing frame (2) and the vehicle body (F). A slide cylinder (Cs) for moving the platform (3) back and forth with respect to the swing frame (2) is interposed between the swing frame (2) and the load platform (3), and the undulating cylinder (Cc) and the slide are mounted. By operating both of the cylinders (Cs) or independently operating the slide cylinders (Cs), the load carrier (3) can be moved to a predetermined position such that the object to be transported (K) on the ground can be loaded on the load carrier (3). The most retracted position (3R) and the most forward position where the loading platform (3) is mounted substantially horizontally on the swing frame (2) in the laid down state. In transportation vehicle which can be driven between the mounting position (3F),
A dumping step of swinging the loading platform (3) together with the swing frame (2) in the upright direction, and a product for driving the loading platform (3) from the last backward tilting position (3R) to the most forward loading position (3F). A single up switch (U-SW) for instructing execution of the input process by operating input to a predetermined up operation position,
A forward limit sensor (S-LS) capable of detecting a first state in which the platform (3) is in the forward limit with respect to the swing frame (2);
A control device capable of controlling the operation of the slide cylinder (Cs) and the undulating cylinder (Cc) based on an operation input to the up switch (U-SW) and a detection output of the forward limit sensor (S-LS) ( C) and at least,
If the controller (C) is detecting the first state by the forward travel limit sensor (S-LS) when the up switch (U-SW) is operated and input to the up operation position. A transportation vehicle, wherein the dumping step is executed, and the loading step is executed if the forward limit sensor (S-LS) is not detecting the first state. A rear end portion of a swing frame (2) extending in the front-rear direction is pivotally supported by a rear portion of the vehicle body (F) so as to be capable of undulating and swinging, and at least a front portion of the luggage carrier (3) is moved forward and backward on the swing frame (2). An undulating cylinder (Cc) that movably engages and oscillates the swing frame (2) together with the loading platform (3) is interposed between the swing frame (2) and the vehicle body (F). A slide cylinder (Cs) for moving the platform (3) back and forth with respect to the swing frame (2) is interposed between the swing frame (2) and the load platform (3), and the undulating cylinder (Cc) and the slide are mounted. By operating both of the cylinders (Cs) or independently operating the slide cylinders (Cs), the load carrier (3) can be moved to a predetermined position such that the object to be transported (K) on the ground can be loaded on the load carrier (3). The most retracted position (3R) and the most forward position where the loading platform (3) is mounted substantially horizontally on the swing frame (2) in the laid down state. In transportation vehicle which can be driven between the mounting position (3F),
A dump lowering step of swinging the loading platform (3) together with the swing frame (2) in the laid-down direction, and driving the loading platform (3) from the most forward mounting position (3F) to the last backward tilting position (3R). A single down switch (D-SW) for instructing execution of the unloading process by operating input to a predetermined down operating position;
A landing sensor (F-LS) capable of detecting that the swing frame (2) is in a second state in which the swing frame (2) lies down on the vehicle body (F);
A control device capable of controlling the operation of the slide cylinder (Cs) and the undulating cylinder (Cc) based on an operation input to the down switch (D-SW) and a detection output of the landing sensor (F-LS) ( C) and at least,
If the control device (C) is detecting the second state by the landing sensor (F-LS) when the down switch (D-SW) is operated and input to the down operation position. The transport vehicle, wherein the unloading step is executed, and the dump lowering step is executed if the landing sensor (F-LS) is not detecting the second state. A rear end portion of a swing frame (2) extending in the front-rear direction is pivotally supported by a rear portion of the vehicle body (F) so as to be capable of undulating and swinging, and at least a front portion of the luggage carrier (3) is moved forward and backward on the swing frame (2). An undulating cylinder (Cc) that movably engages and oscillates the swing frame (2) together with the loading platform (3) is interposed between the swing frame (2) and the vehicle body (F). A slide cylinder (Cs) for moving the platform (3) back and forth with respect to the swing frame (2) is interposed between the swing frame (2) and the load platform (3), and the undulating cylinder (Cc) and the slide are mounted. By operating both of the cylinders (Cs) or independently operating the slide cylinders (Cs), the load carrier (3) can be moved to a predetermined position such that the object to be transported (K) on the ground can be loaded on the load carrier (3). The most retracted position (3R) and the most forward position where the loading platform (3) is mounted substantially horizontally on the swing frame (2) in the laid down state. In transportation vehicle which can be driven between the mounting position (3F),
A dumping step of swinging the loading platform (3) together with the swing frame (2) in the upright direction, and a product for driving the loading platform (3) from the last backward tilting position (3R) to the most forward loading position (3F). The loading step can be executed by an operation input to a predetermined up operation position, and a dump lowering step for swinging the loading platform (3) together with the swing frame (2) in the laid-down direction; A single up / down switch (3) capable of instructing execution of the unloading process for driving 3) from the most forward mounting position (3F) to the last backward tilting position (3R) by operating input to a predetermined down operating position. UD-SW),
A forward limit sensor (S-LS) capable of detecting a first state in which the platform (3) is in the forward limit with respect to the swing frame (2);
A landing sensor (F-LS) capable of detecting a second state in which the swing frame (2) lies down on the vehicle body (F);
For each operation input of the up / down switch (UD-SW) to the up operation position and the down operation position, and for each detection output of the forward limit sensor (S-LS) and the landing sensor (F-LS). And a control device (C) capable of controlling operation of the slide cylinder (Cs) and the undulating cylinder (Cc) based on
The control device (C) may detect that the forward limit sensor (S-LS) is detecting the first state when the up / down switch (UD-SW) is operated and input to the up operation position. For example, the dumping step is executed, but if the forward limit sensor (S-LS) is not detecting the first state, the loading step is executed, and the up-down switch (UD-SW). Is input to the down operation position, if the floor landing sensor (F-LS) is detecting the second state, the lowering step is executed, but the floor landing sensor (F-LS) is executed. ) Is not detecting the second state, the dump lowering step is executed.