JP2004306958A - Crawler-type truck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve an appearance by arranging exhaust pipes in the interior of a packing case receiver, and to arrange hoses for supplying pilot pressure oil that are laid on each member of a hydraulic system, and to protect these hoses. <P>SOLUTION: In a crawler-type truck, at the top front side of a body frame 1 of a travelling device comprised of the body frame 1 and a crawler 2, an operation section 18, and an engine hood 17 having an engine E inside, are disposed, and a vertical rotary-type packing case 10 is disposed on a packing case receiver 8 via the packing case receiver 8 in longitudinal direction, on left and right main frames 1L, 1R comprising the body frame 1. The packing case receiver 8 is made of a sequence of continuous pipe structure in which the exhaust pipes 12 provided across the receiver 8 is included. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a configuration of a crawler type transport vehicle.

The main body frame structure of the crawler-type carrier has left and right crawler frames 1 on the outer sides of a main frame 1 ″ L · 1 ″ R having front and rear lengths parallel to each other, as shown in the main body frame 1 ″ shown in FIGS. "La.1" Ra are arranged and connected by a reinforcing frame in the left-right direction.Above the main frame 1 "L.1" R, the packing box It is placed on a sleeper 9 disposed above the frame 1 "L.1" R. Conventionally, a pipe such as an exhaust pipe 12 is formed on each main frame 1 "L.1" R. Are erected on the body frame 1 "L.1" R on the outside of the main frame 1 "R," and the sleepers 9 are mounted thereon, and the sleepers 9 are attached to the main frame 1 ". It is arranged above the pipe such as the exhaust pipe 12 on L.1 "R. , As the actual fair 7-015829, JP-structure for mounting the packing boxes on the packing box receiving erected vertically form above the body frame can also be seen.
Japanese Utility Model Publication No. 7-015829

In the structure of a main body frame of a crawler-type carrier, in a conventional structure in which an exhaust pipe or the like is piped on a main frame and a sleeper is disposed thereon, a high-temperature exhaust pipe exerts a strong influence on the sleeper.
On the other hand, when the exhaust pipe is not piped on the main frame, there is a gap between the packing box receiver and the packing box receiver that communicates the outside and the inside of the main frame due to the height difference between the sleeper and the main frame. However, there is a problem that earth and sand enter the inside of the main frame. This is especially true if no exhaust pipe or the like is provided on the main frame.
The structure disclosed in Japanese Utility Model Publication No. 7-015829 is the same, and has a bad effect of earth and sand intrusion. When earth and sand enter this part, pumps and valves of the driving system are disposed between the left and right main frames, and there is a possibility that the earth and sand adhere to these parts and cause adverse effects such as malfunction. In particular, since the earth and sand are well wound near the upper surface of the crawler, a structure for preventing earth and sand from entering is desired.

Next, means for solving the problem will be described.
According to the first aspect, the operating unit 18 and the hood 17 that houses the engine E are disposed on the front upper portion of the main body frame 1 of the traveling device formed by the main body frame 1 and the crawler 2 to form the main body frame 1. In a crawler type transport vehicle in which a vertically rotatable packing box 10 is disposed on the left and right main frames 1L and 1R via a packing box receiver 8 in the front-rear direction, the packing box The receiver 8 has a continuous pipe structure that can include the exhaust pipes 12 arranged along the front and rear sides.

  According to a second aspect, in the crawler-type carrier according to the first aspect, a sleeper 9 is placed on the packing case receiver 8 without any gap in the front-rear direction.

The present invention has the following effects because the transport vehicle is configured as described above.
The operating unit 18 and the hood 17 containing the engine E are arranged on the upper front side of the main body frame 1 of the traveling apparatus constituted by the main body frame 1 and the crawler 2 to constitute the main body frame 1. In a crawler type transport vehicle in which a vertically rotatable packing box 10 is disposed on the left and right main frames 1L and 1R via a packing box receiver 8 in the front-rear direction, the packing box Since the receiver 8 has a continuous pipe structure that can include the exhaust pipes 12 arranged along the front and rear, the exhaust pipe can be piped inside the packing box receiver, so that the appearance is improved.
Also, hoses for supplying pilot pressure oil can be provided to each hydraulic system member, and these hoses can be protected.

Since the sleeper 9 is placed in the front-rear direction without any gap on the cargo box receiver 8 as in claim 2, the cargo box receiver is interposed between the exhaust pipe and the sleeper piped inside the cargo box receiver. This eliminates the problem that heat from the exhaust pipe, which becomes hot due to the passage of high-temperature exhaust gas, is transmitted to the sleepers.
In addition, since the packing case receiver is a continuous tube, and the sleeper is mounted thereon without any gap, there is no gap on the main frame between the outside and the inside of the vehicle body, and therefore, the lower traveling device has The problem that earth and sand enter the inside of the vehicle body (main body frame) from the outside and adhere to the members of the drive system disposed between the left and right main frames is eliminated.

An embodiment of a carrier according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a perspective view of a truck, FIG. 2 is a right side view, FIG. 3 is a left side view, FIG. 4 is a plan view, FIG. 5 is a rear view, FIG. 6 is a front view, and FIG. 8 is a side view of the main body frame 1, FIG. 9 is a plan view thereof, FIG. 10 is a rear view thereof, FIG. 11 is a side view showing an arrangement structure of each member in the main body frame 1, and FIG. FIG. 13 is a rear view of the same, FIG. 14 is a side view of the main body frame 1 ′, FIG. 15 is a plan view of the same, FIG. 16 is a side view of a conventional main body frame 1 ″, FIG. 19 is a front plan view showing the disposition position of the battery B, FIG. 19 is a front view thereof, FIG. 20 is a side view showing an assembly structure of the idler 7, FIG. 21 is a front sectional view thereof, and FIG. FIG. 23 is a schematic side view of a truck showing a tilt direction and a rotation direction of wheels, and FIG. FIG. 24 is a flowchart showing a method of determining whether the vehicle is going downhill or uphill based on the relationship between the rearward inclination direction and the rotation direction of the wheels, FIG. 24 is a flowchart of downhill determination, FIG. 25 is a logic circuit diagram of downhill determination, and FIG. FIG. 27 is a hydraulic and electric circuit diagram showing a downhill speed reduction mechanism groove by reducing the discharge amount of the traveling hydraulic pump P. FIG. 27 is a hydraulic diagram showing a downhill speed reduction mechanism by operating a movable swash plate of a traveling hydraulic motor M whose initial state is a first speed stage. FIG. 28 is a hydraulic and electric circuit diagram showing a downhill speed reduction mechanism by operating a movable swash plate of a traveling hydraulic motor M in an initial state of a second speed stage.

  First, the external appearance of the crawler-type carrier will be schematically described with reference to FIGS. In the main body frame 1 forming the chassis, crawler frames 1La and 1Ra are respectively disposed outside the left and right parallel main frames 1L and 1R, and a driving sprocket 3 is provided at the front end of each crawler frame 1La and 1Ra. Are suspended at the lower edge, and an extendable idler frame 5 is extended from the rear end (to extend and retract the idler cylinder 6 shown in FIG. 12). The idler 7 is suspended from the rear end, and the crawler 2 is wound around these. On each of the main frames 1L and 1R, a cargo box receiver 8 is disposed in the front-rear direction, and a sleeper 9 is mounted thereon. At the rear end of the upper surface of the main frames 1L and 1R, packing box brackets 1g and 1g are formed to pivotally support the vertical rotation fulcrum shaft 10a of the packing box 10, and a cylinder described below between the main frames 1L and 1R. Between the brackets 1f, 1f and cylinder brackets 8b, 8b formed at the bottom of the packing box 10, packing box rotating cylinders 11, 11 are pivotally connected, and the packing box rotating cylinders 11, 11 are connected. The packing box 10 is rotated by the expansion and contraction drive of. At the time of storage, the packing box 10 is placed on the sleeper 9.

The front structure of the crawler type transport vehicle will be described.
An operation unit frame 15 is provided on the front of the main frames 1L and 1R, and a hood 17 is mounted on the operation unit frame 15. Using the upper surface of the frame 9, a platform 16 serving as a scaffold for inspection of an operator is formed. A cabin 18 is mounted on the left side of the platform 16, and a seat 19 and the like are arranged therein.

The outline has been described above. Next, the structure of the main body frame 1 shown in FIGS. 8 to 13 and the traveling drive system disposed inside the main body frame 1 will be described.
In the main body frame 1, left and right crawler frames 1La and 1Ra are disposed outside each of the left and right main frames 1L and 1R. Between the left and right crawler frames 1La and 1Ra, three front and rear main reinforcing frames of a front reinforcing frame 1b, a middle reinforcing frame 1c, and a rear reinforcing frame 1d are provided horizontally. At the front ends of the left and right crawler frames 1La and 1Ra, left and right traveling hydraulic motors ML and MR (collectively referred to as traveling hydraulic motors M) connected to the left and right driving sprockets 3.3 are disposed. The disposition parts are connected to each other by an oil pan guard 1a. The front reinforcement frame 1b also serves as a mounting table for the engine E, and the oil pan guard 1a and the front reinforcement frame 1b are provided along the front and rear of an oil pan Ea which is vertically provided at the bottom of the engine E, so that the oil Has become a bread protection frame. Further, a rear frame 1e is horizontally provided at a rear end between the left and right main frames 1L and 1R, and cylinder brackets 1f and 1f for pivotally supporting the base end of the packing box rotating cylinder 9 on the left and right of the rear frame 1e. Is attached.

Here, as another embodiment of the main body frame, a main body frame 1 'shown in FIGS. 14 and 15 will be described.
Similarly to the main frame 1, left and right crawler frames 1'La, 1'Ra are arranged outside each of the left and right main frames 1'L, 1'R, and an oil pan guard 1'a and a front reinforcing frame 1'b. The middle reinforcement frame 1'c and the rear reinforcement frame 1'd are laid laterally to connect the main frames 1'L, 1'R and the crawler frames 1'La, 1'Ra. Similarly, a rear frame 1'e and a cylinder bracket 1'f for pivotal support of the base end of the cylinder 11 are connected between the rear ends of 'L · 1'R, and the main frame 1'L ・ 1'R is connected. A packing box bracket 1'g for pivotally supporting the rotation fulcrum shaft 10a of the packing box 10 is formed at the upper portion of each rear end. The method of disposing the engine is the same, and an oil pan guard 1'a and a front reinforcing frame 1'b are provided along the oil pan Ea vertically extending from the engine E. Note that, in the main body frame 1 ', the packing box receiver uses a plurality of conventional packing box receivers 8' and 8 '(the same as those shown in FIGS. 16 and 17).

  As shown in FIGS. 11 and 12, a left traveling hydraulic pump PL and a right traveling hydraulic pump PR for supplying hydraulic pressure to the left traveling hydraulic motor ML and the right traveling hydraulic motor MR are connected to the rear of the engine E in the main body frame 1. The traveling hydraulic pump P is provided in series. In the case of the main body frame 1, a hydraulic oil tank LT is provided along the rear reinforcing frame 1e, and hydraulic hose piping is provided from the hydraulic oil tank LT to the traveling hydraulic pump P and other components. Further, a control valve CV is provided inside the left traveling frame 1L, and hydraulic hoses are connected to the traveling hydraulic pump P and various parts. The above drive system arrangement structure is the same in the main body frame 1 '.

  In the main body frame 1, as shown in FIGS. 11 to 13, a muffler 13 is provided on the rear frame 1e, and the muffler 13 is formed in a tubular shape on the right main frame 1R from the engine E. An exhaust pipe 12 is provided so as to penetrate the inside of the cargo box receiver 8. Although high-temperature exhaust gas passes through the exhaust pipe 12, the upper surface of the cargo box receiver 8 is interposed between the exhaust pipe 12 and the upper sleeper 9 to prevent the influence of the high temperature from propagating to the sleeper 9. I have. In addition, a hydraulic hose cannot be piped near the exposed exhaust pipe, so that the piping space for the hydraulic hose is also limited. By arranging in the pipe 8, a hydraulic hose can be laid in the vicinity thereof, that is, the degree of freedom of piping of the hydraulic hose is improved.

  Pilot hoses 14, 14,..., Which are hydraulic hoses for pilot pressure, are piped in the cargo box receiver 8 on the left main frame 1L, and are pierced on the inner surface of the cargo box receiver 8. Are connected to the traveling hydraulic pump P and the control valve CV through the notches 8a. Since the notch holes 8a are formed in the inner surface, it is possible to ensure the prevention of intrusion of earth and sand as described above. It should be noted that which of the left and right packing box receivers 8, 8 is to be fitted with the exhaust pipe 12 and the pilot hose 14 is appropriately set.

  On the other hand, in the main frame 1 'shown in FIGS. 14 and 15, the main frame itself is used as an exhaust pipe. That is, the main frame 1'R (in some cases, the left main frame 1'L), which is a square tube, is used as the exhaust pipe. From the engine E, the exhaust introduction pipe 20 is connected to the upper surface of the front part of the right main frame 1'R, and the exhaust extension pipe 21 is extended from the upper surface of the rear part of the right main frame 1'R to the muffler 13. Connected.

Next, the configuration and effects of the cargo box receiver 8 used for the main body frame 1 will be described.
Conventionally, as employed in the main frame 1 ″ shown in FIGS. 16 and 17 (also used in the main frame 1 ′ shown in FIGS. 14 and 15), , And a plurality of packing case holders 8 ', 8', etc. is erected, and the sleepers 9 are arranged on all the packing case holders 8 ', 8', etc. Also, the main body frame 1 ' Although the right main frame 1'R is used as an exhaust pipe, the load is conventionally placed on the right main frame 1 "R (or the left main frame 1" L) as shown in FIGS. The exhaust pipe 12 is piped inside the box receivers 8 ', 8', etc. In this piping structure of the exhaust pipe 12, the sleeper 9 is disposed immediately above, so that the high temperature of the exhaust pipe 12 is The exhaust pipe 12 may be piped to a location other than on the main frame 1 ″, or the left main frame 1 ″ in FIG. When the piping such as the exhaust pipe is not made as in the above, the main frame 1 "L.1" R There is a gap that connects the outside and the inside of the 1 "R, and there is a possibility that the earth and sand S riding on the upper surface of the crawler 2 may enter the inside through this gap as shown in FIG.

  In this respect, the packing case receiver 8 employed in the main body frame 1 has a continuous tubular shape, and if the sleeper 9 is placed and fixed thereon without any gap, the main frames 1L and 1R as in the conventional case are provided. The space connecting the inside and outside of the building has been eliminated, and the intrusion of earth and sand can be eliminated. Further, as described above, the notches 8a, 8a,... For fitting the pilot hoses 14 and the like are formed in the inner surface, and the outer surface is flat without the notch, and the earth and sand from the outside is formed. Can be prevented.

Next, the piping structure of the hydraulic hose for the traveling hydraulic motors ML and MR will be described.
For the travel hydraulic motors ML and MR, a travel drive hydraulic hose H1 for supplying travel drive hydraulic oil from the travel hydraulic pumps PL and PR is provided, and a brake valve attached to the travel hydraulic pump P is provided. The brake hydraulic hose H2 and the drain hose H3 are piped from this and the like. In the main body frame 1, the brake hydraulic hose H2 and the drain hose H3 are provided along the oil pan guard 1a. Conventionally, each hydraulic hose H1, H2, H3 is piped in a state of being bent in a space without being along a frame (a main frame 1 "L, 1" R, an oil pan guard 1 "a, or the like). Since it passed the side and under E, there was a risk of interference with the engine when the direction of the hose fluctuated due to some beat, but by arranging it on the oil pan guard 1a in this way, the piping becomes The position is fixed and interference is avoided.

  Further, the oil pan guard 1'a of the main body frame 1 'shown in FIGS. 14 and 15 has a tubular shape, and hydraulic hoses H2 and H3 for the left and right traveling hydraulic motors ML and MR are provided with piping therein. Therefore, the protection of these hydraulic hoses is further improved.

Next, the divided structure of the idler 7 will be described with reference to FIGS.
The idler 7 is configured by bolting four-part peripheral members 7b, 7b,... On the outer periphery of a central member 7a directly circulating on the central axle 22. The idler is the largest of the wheels wound on the crawler, and if the vehicle body becomes larger, it becomes very large and heavy if integrated. Further, the crawler 2 does not expand and contract, and it is not easy to remove the idler fitted to the core bar projection 2a protruding from the crawler 2 or to attach the idler. In this embodiment, by dividing the peripheral portion, each of the members 7a, 7b, 7b,... Becomes light and small, and can be easily assembled or disassembled by attaching and detaching bolts. .

  First, when removing the idler 7, by removing the peripheral members 7b from the central member 7a, a gap is formed between the remaining central member 7a and the crawler 2, and the remaining central member 7a itself is removed. Is also easier to remove. Further, at the time of mounting, one peripheral member 7b is screwed at a position where there is no interference with the crawler 2 on the outer peripheral portion of the central member 7a. Thereafter, the driving sprocket 3 is rotated by a fixed amount, the peripheral member 7b is fitted to the cored bar projection 2a of the crawler 2, and the outer peripheral portion of the central member 2a adjacent thereto is placed at the position where one of the peripheral members 7b is previously attached ( (A position where the peripheral member 7b does not interfere with the crawler 2), and the peripheral member 7b adjacent to the previously attached peripheral member 7b is attached to this portion. Further, the rotation of the driving sprocket 3 and the attachment of the peripheral member 7b are repeated, and finally, the front peripheral member 7b is attached to the central member 7a, and the idler 7 is attached.

Next, the location of the battery B at the front of the vehicle body will be described with reference to FIGS. 11, 18, and 19. FIG.
Conventionally, the battery B provided in the hood is mounted under the floor of the platform 16 in the type in which the platform 16 is provided as in the present embodiment. On the platform 16, the worker can easily open the floor in a stable posture and perform maintenance work on the battery B. Further, a radiator R is disposed in the front of the bonnet 17 to take in outside air from the front end of the bonnet 17, and the battery B below the floor of the platform 16 faces the outside air inlet to the radiator R (see FIG. In the present embodiment, the heat radiation can be favorably maintained by being mounted on the platform 16 at substantially the center on the left and right sides.

Lastly, an automatic deceleration mechanism for a crawler-type carrier on a downhill will be described.
In the crawler-type carrier according to the present embodiment, the seat 19 in the operation unit 18 is turned back and forth (the operation levers and the like around it are also turned over), and the worker sitting on the seat 19 looks backward and looks backward. You can also. For this reason, the reverse drive is frequently performed. However, since the packing box 10 is located in front of the worker particularly when the vehicle is moving backward, the visibility is poor, and even if the user approaches a downhill, the manual deceleration operation may be delayed without being noticed immediately. In order to solve this problem, the crawler-type carrier according to the present embodiment is provided with a mechanism for automatically decelerating on a downhill.

  First, means for determining whether the vehicle is going downhill is required. In this case, it is determined whether the vehicle is going downhill based on the detection of the direction of the front-back inclination of the vehicle body and the detection of the rotation direction of the driving sprocket 3 (the direction of discharging the hydraulic oil to the traveling hydraulic motor M). That is, as shown in FIG. 22, when the rear portion of the vehicle body (the side where the packing box 10 is mounted) is inclined downward, + is given, and when the front portion (the operation portion 18 side) is inclined downward, −. Regardless of whether the drive sprocket 3 is turned back and forth.), The rotation direction of the drive sprocket 3 in the forward direction is defined as +. Accordingly, as shown in FIG. 23, when the sign indicating the direction of the front-rear inclination of the vehicle body does not match the sign indicating the rotational direction of the drive sprocket 3, it is determined that the vehicle is going downhill.

In addition to the determination of whether the slope is downhill, whether the inclination angle is equal to or greater than a certain angle, and if the inclination angle is equal to or greater than a certain angle, it detects whether the time of incline is equal to or greater than a certain time, Is output to the speed reduction mechanism when. FIG. 24 is a flowchart showing these procedures. In this flowchart, whether the attitude of the machine is forward or not is determined as described above based on the ± determination of the longitudinal inclination direction of the vehicle body, and whether the machine is traveling forward or backward is determined based on the rotation direction of the drive sprocket 3 as described above. Based on ± judgment. Further, theta is the detection angle, | theta | is (angle with respect to a vertical line when the upward forward descending front) tilt angle, theta ₁ is a 0 <θ ₁ <90 ° in angle of inclination of the criteria, theta When <0, the vehicle body is lowered forward, and when θ> 0, the vehicle is raised forward. In addition, T is | θ |> θ ₁ of duration, t indicates whether the reference time if you want to slow down.

The logic circuit for downhill determination is configured as shown in FIG. First, a longitudinal inclination determination of the vehicle body, for the detection of the inclination angle, is provided with the tilt angle sensor 23, the inclination angle detected by the angle of inclination sensor 23 | theta | when the> theta _1, its duration T A determination timer 24 is provided. From the inclination angle sensor 23, an output terminal for outputting in each case of θ> + θ ₁ and θ <−θ ₁ with respect to the detected inclination angle θ is connected to an input terminal of the timer 24. An output terminal is provided from the timer 24 for outputting when the duration time becomes equal to or longer than t in each case.

  On the other hand, two traveling drive hydraulic hoses H1a, H1b, H1c, H1d are piped from the traveling hydraulic pumps PL, PR to the left and right traveling hydraulic motors ML, MR, respectively, and pressure detection sensors 25, 26 are respectively provided.・ 27 and 28 are provided. When the traveling drive hydraulic hoses H1a and H1c are on the discharge side, the traveling hydraulic motor M (ML / MR) is driven forward, and when the traveling drive hydraulic hoses H1b and H1d are on the discharge side, the drive is reverse. The output terminals of the pressure detection sensors 25 and 29 are connected to the input terminals of the AND circuit 29 as a circuit for outputting when the traveling hydraulic motor M is driven forward (the rotation direction of the driving sprocket 3 is +). The output terminals of the pressure detection sensors 26 and 27 are connected to the input terminals of the AND circuit 30 as an output circuit in the case of the reverse drive. , And the output from the AND circuit 30 is determined to be the reverse drive.

From the timer 24, theta <output end - [theta] ₁ is output when continuous or t, and connected to an input terminal of the AND circuit 31 together with the output terminal of the AND circuit 29, whereas, θ> + θ ₁ or more t The output terminal output when the operation is continued is connected to the input terminal of the AND circuit 32 together with the output terminal of the AND circuit 30. When the vehicle is moving forward and the vehicle is moving forward, an output is outputted from the AND circuit 31. When the vehicle is moving forward and the vehicle is moving backward, the output is outputted from the AND circuit 32. In any case, the output terminals of the AND circuits 31 and 32 are connected to the input terminals of the OR circuit 33 in order to determine that the vehicle is going downhill and output the signal to the speed reduction mechanism. When output from the OR circuit 33, deceleration on a downhill is performed.

  Next, the speed reduction mechanism when it is determined that the vehicle is going downhill will be described. When it is determined that the vehicle is going downhill, the following three methods can be considered to reduce the speed. The first is a method of reducing the engine speed, the second is a method of reducing the discharge amount of the traveling hydraulic pump P, and the third is a movable swash plate of the traveling hydraulic motor M (the traveling of the crawler-type transport vehicle of the present embodiment). The hydraulic motor M is of a variable displacement type and its capacity can be set in two stages.

  For reducing the engine speed, a deceleration mechanism is used. This machine is provided with a deceleration mechanism that lowers the engine speed to an idling speed by operating a switch in conjunction with a stop of the work, and returns to the original speed as soon as the work is started. By using this deceleration mechanism, it is only necessary to set so as to reduce the engine speed when it is determined that the vehicle is going downhill, and to return to the original speed again when no downhill is detected.

  The reduction mechanism by reducing the discharge amount of the traveling hydraulic pump P is as shown in FIG. When the downhill determination switch SW is turned on when the downhill determination switch SW is turned on, the pilot voltage is sent to the electromagnetic pilot hydraulic valves 36 to 39 for controlling the hydraulic pressure to the movable swash plate operation actuators 34 and 35 of the traveling hydraulic pumps PL and PR. That is, the inclination of the movable swash plate is reduced, that is, the discharge amount is reduced.

  The deceleration mechanism by moving the movable swash plate of the traveling hydraulic motor M is as shown in FIGS. 27 and 28. Both the traveling hydraulic motors M in FIGS. 27 and 28 change the inclination of the movable swash plate into two stages, a first speed stage (low speed stage, that is, a large inclination) and a second speed stage (high speed stage, that is, a small inclination). The setting shown in FIG. 27 is such that the initial position is the first speed, and the movable swash plate is switched to the second speed by hydraulic pressure during high-speed running. The initial position shown in FIG. 28 is the second speed. When the driving force is required, the gear is switched to the first gear by hydraulic pressure. Each of them has a deceleration structure that switches the movable swash plate to the first speed when it is determined that the vehicle is going downhill when the vehicle is in the second speed.

  The speed reduction mechanism of FIG. 27 will be described. The movable swash plates of the traveling hydraulic motors ML and MR are provided with hydraulic cylinders 40 and 41 as actuators for operating the movable swash plate, respectively. The movable swash plate is set in. If it is determined that the vehicle is going downhill, pilot hydraulic oil is drawn from the hydraulic pilot hydraulic valves 42 and 43 for controlling the hydraulic pressure of the hydraulic cylinder 25, and hydraulic oil is drawn from the hydraulic cylinders 40 and 41. It can be switched to tiers.

  The speed reduction mechanism of FIG. 28 will be described. The hydraulic cylinders 44 and 45, which are movable swash plate operation actuators attached to the movable swash plates of the traveling hydraulic motors ML and MR, switch the movable swash plate from the second speed stage to the first speed stage by supplying pressure oil. . When it is determined that the vehicle is going downhill and the downhill determination switch SW is turned on, the electromagnetic pilot hydraulic valve 46 for controlling the hydraulic pressure of the hydraulic cylinders 44 and 45 is switched to supply hydraulic oil to the hydraulic cylinders 44 and 45. The movable swash plate can be switched from the second gear to the first gear.

It is a perspective view of a transport vehicle. It is a right view similarly. It is a left view similarly. FIG. FIG. FIG. FIG. FIG. 2 is a side view of the main body frame 1. FIG. FIG. FIG. 3 is a side view showing an arrangement structure of each member in the main body frame 1. FIG. FIG. It is a side view of main-body frame 1 '. FIG. It is a side view of the conventional main body frame 1 ". FIG. FIG. 3 is a front plan view of a transport vehicle showing a position where a battery B is provided. FIG. It is a side view which shows the assembly structure of an idler 7. FIG. FIG. 3 is a schematic side view of the transport vehicle showing a front-rear inclination direction of a vehicle body and a rotation direction of wheels. 4 is a chart showing a method of determining whether the vehicle is going downhill or uphill based on the relationship between the front-back inclination direction of the vehicle body and the rotation direction of wheels. It is a flowchart figure of downhill determination. It is a logic circuit diagram of downhill determination. FIG. 4 is a hydraulic and electrical circuit diagram showing a downhill speed reduction mechanism groove by reducing the discharge amount of a traveling hydraulic pump P. FIG. 4 is a hydraulic circuit diagram showing a downhill speed reduction mechanism by operating a movable swash plate of a traveling hydraulic motor M in an initial state as a first speed stage. FIG. 4 is a hydraulic and electric circuit diagram showing a downhill speed reduction mechanism by operating a movable swash plate of a traveling hydraulic motor M that sets an initial state to a second speed.

Explanation of reference numerals

E Engine Ea Oil pan M Travel hydraulic motor P Travel hydraulic pump H1 Travel drive hydraulic hose H2 Brake hose H3 Drain hose B Battery 1.1 'Main frame 1L-1'L Left main frame 1R / 1'R Right main frame 1La・ 1′La Left crawler frame 1Ra ・ 1′Ra Right crawler frame 1a ・ 1′a Oil pan guard 8 Packing box receiver 8a Notch hole 9 Sleeper 10 Packing box 12 Exhaust pipe 13 Muffler 14 Pilot hose 15 Front frame 16 Platform

Claims (2)

  An operation unit 18 and a hood 17 that houses the engine E are disposed on the front upper portion of the main body frame 1 of the traveling device constituted by the main body frame 1 and the crawler 2. In a crawler-type transport vehicle in which a vertically rotatable packing box 10 is arranged on the 1R via the packing box receiver 8 in the front-rear direction, the packing box receiver 8 is moved back and forth. A crawler-type carrier having a continuous pipe structure capable of including an exhaust pipe 12 provided alongside the crawler.   The carrier according to claim 1, wherein the sleeper (9) is placed on the packing case receiver (8) without any gap in the front-rear direction.

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