Maintenance tool

Abstract

To provide a maintenance tool which enables a person to exchange belts.SOLUTION: A maintenance tool 5 is used when belts 61 driving at least one of a fan 66 of a driving source 18 of a vehicle 1 and auxiliaries 63, 64 are exchanged, and includes: a fixing part 80 which is removably fitted to a tensioner 71 rotatably supporting a tension pulley 67 imparting tensile force to a belt 61; a support part 84 removably fitted to the vehicle body 3 of the vehicle 1; a pulling part 86 movably disposed in the support part 84; and a transmission part 92 stretched over the fixing part 80 and the pulling part 86. The fixing part 80 is moved via the transmission part 92 by moving the pulling part 86, and the tension pulley 67 is moved in the direction in which the tensile force attenuates.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a maintenance tool. [Background technology]

[0002] 2. Description of the Related Art Known examples of vehicles that travel on roads include passenger vehicles such as automobiles, commercial vehicles such as trucks, and work vehicles such as hydraulic excavators, track loaders, and tractors.

[0003] As an example of a drive source for the vehicle, a configuration in which an engine (gasoline engine, diesel engine, etc.) is used has conventionally been widespread. Recently, however, configurations in which an electric motor is used instead of or in addition to the engine are also becoming widespread.

[0004] A typical engine is equipped with auxiliary devices such as an alternator, water pump, and compressor (if equipped with air conditioning). Normally, output (rotational force) is taken from a crank pulley connected to the crankshaft, and the auxiliary devices are driven via one or more belts. In cases where a cooling fan is directly attached to the engine, the above-mentioned belt-driven configuration has been widely used, and the belt is often referred to as a "fan belt."

[0005] As an example, a rubber V-belt with a resin core is used for the above belt. The belt needs to be used with the appropriate tension applied, but it is very time-consuming for an operator to periodically check and adjust the tension. For this reason, various mechanisms (auto-tensioners) that automatically adjust the tension applied to the belt via a tension pulley, i.e., keep it at an appropriate value, have been developed (Patent Document 1: JP 2021-148110 A). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2021-148110 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, since the above-mentioned belts are consumables, they need to be replaced periodically or when they deteriorate or become damaged. Belt replacement work is generally performed through a maintenance opening provided in the engine room. However, especially in work vehicles, there are cases where two people are forced to work together when replacing the belt due to the restrictions of the maintenance opening (position, shape, etc.). Specifically, one person uses a rotary tool (socket wrench, box wrench, etc.) to move the tension pulley and maintain the state in which the tension is reduced, while the other person installs a fixing device (driver, rod-shaped pin, etc.) to temporarily fix the moved tension pulley in place. Therefore, it is not possible to replace the belt by one person alone, which results in an extremely inefficient work. [Means for solving the problem]

[0008] The present invention has been made in consideration of the above circumstances, and has an object to provide a maintenance tool that enables a person to replace a belt by himself.

[0009] The present invention solves the above problems by the solution means described below as one embodiment.

[0010] A maintenance tool according to one embodiment is a maintenance tool used when replacing a belt that drives at least one of the fan or auxiliary equipment of a vehicle's drive source, and comprises a fixed part that is removably attached to a tensioner that rotatably supports a tension pulley that applies tension to the belt, a support part that is removably attached to the body of the vehicle, a tensioning part that is movably arranged on the support part, and a transmission part that spans between the fixed part and the tensioning part, and is configured to move the tensioning part to move the fixed part via the transmission part, thereby moving the tensioning pulley in a direction in which the tension is attenuated.

[0011] With the above configuration, the fixed part, i.e., the tension pulley, can be moved in the tension reduction direction via the transmission part by moving the tension part, and the fixing device that temporarily fixes the position of the tension pulley can be attached while maintaining that state. Therefore, it is possible for one person to replace the belt.

[0012] It is also preferable that the tensioning portion is provided with a locking portion to which the transmission portion is locked and a threaded portion is formed at a predetermined position, a nut is screwed onto the threaded portion, and the axial end face of the nut is positioned so as to abut against the support portion, and the tensioning portion is moved by rotating the nut.

[0013] In addition, it is preferable that the support portion is provided with a guide groove that prevents the tension portion from rotating together with the nut when the nut is rotated and guides movement in a predetermined direction.

[0014] It is also preferable that the tension pulley be moved in the direction in which the tension is attenuated and temporarily fixed in position by a fixing device, and that the fixing device be attached to the fixed portion by a chain, wire, rope, or wire.

[0015] In addition, it is preferable that the fixing portion is provided with a square drive that can be fitted into a fitting hole for a square drive of a socket wrench provided in the tensioner.

[0016] In addition, it is preferable that the support portion is configured to be fixed to the vehicle body by bolting using bolt holes for attaching the bracket to the vehicle body with a bracket that supports an inspection cover provided on the vehicle body so that it can be opened and closed being removed.

[0017] It is also preferable that the transmission section is constructed using a wire, with locking rings or hooks provided on both ends. Effect of the Invention

[0018] According to one embodiment of the maintenance tool, the tension pulley can be moved in the tension reduction direction and maintained in that state, and a fixing device can be attached to temporarily fix the tension pulley in that state. Therefore, it is possible to replace the belt by one person, especially in a work vehicle or the like that has many restrictions regarding openings for maintenance. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view showing an example of a vehicle to which a maintenance tool according to an embodiment of the present invention is applied. [Diagram 2] FIG. 2 is a perspective view showing an example of a vehicle body and a drive source of the vehicle in FIG. [Diagram 3] FIG. 3 is a perspective view showing an example of a drive source of the vehicle in FIG. [Figure 4] FIG. 4 is a perspective view showing an example of a maintenance tool according to an embodiment of the present invention. [Diagram 5] FIG. 5 is an enlarged view of the maintenance tool of FIG. [Figure 6] 6A and 6B are enlarged views of the maintenance tool in FIG. 4, with FIG. 6A being an exploded view and FIG. 6B being an assembly view. [Figure 7]FIG. 7 is a perspective view of the maintenance tool of FIG. 4 in a mounted state. [Figure 8] FIG. 8 is an explanatory diagram of a state before the tension pulley is moved using the maintenance tool of FIG. [Figure 9] FIG. 9 is an explanatory diagram of a state after the tension pulley has been moved using the maintenance tool of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an example of a vehicle 1 to which a maintenance tool 5 according to an embodiment of the present invention is applied. FIG. 4 is a perspective view showing an example of a maintenance tool 5 according to an embodiment of the present invention. For convenience of explanation, arrows may be used in the drawings to indicate up / down, left / right, and front / rear directions. In all the drawings for explaining the embodiment, members having the same function are given the same reference numerals, and repeated explanations thereof may be omitted.

[0021] The maintenance tool 5 according to this embodiment is a tool used when replacing a belt that drives at least one of the fan or accessories of the drive source 18 of the vehicle 1. Note that, in the following description, a work vehicle (e.g., a hydraulic excavator) is taken as an example of the vehicle 1, and an engine (e.g., a diesel engine) is taken as an example of the mounted drive source 18, but the present invention is not limited to these.

[0022] First, as shown in FIG. 1, a work vehicle (hydraulic excavator) 1 has a vehicle body including a lower body 2 and an upper body 3 disposed on the lower body 2 (the lower body 2 and the upper body 3 may be integrally configured).

[0023] The work vehicle 1 is also equipped with working devices 12, 14 that are attached to the lower body 2 and upper body 3 and are operated by hydraulic pressure (hydraulic oil at a specified pressure). The lower body 2 is equipped with a traveling device 10 that drives the vehicle. The upper body 3 is equipped with a driver's cab 16 at the front where an operator rides in and operates the vehicle for traveling and work. In addition, the upper body 3 is equipped with an engine room 20 at the rear in which an engine 18, a hydraulic pump, etc. are housed.

[0024] As an example of the traveling device 10, a pair of left and right crawlers 26 driven by a traveling hydraulic motor 28 is provided. Note that a configuration in which tires are provided instead of the crawlers 26 (not shown) may also be used.

[0025] An example of the working implement 12 is a blade 30 driven by a hydraulic cylinder 40. An example of the working implement 14 is a boom 32, an arm 34, and a detachable attachment 36, which are driven by hydraulic cylinders 42, 44, and 46, respectively. Note that, although a bucket is shown as an example of the attachment 36, the present invention is not limited to this.

[0026] The engine 18 according to this embodiment is arranged horizontally in the engine compartment 20 (i.e., an arrangement in which the crankshaft is parallel to the left-right direction of the upper body 3) and is fixed via an engine foot (not shown) onto the main body frame 22. Here, Fig. 2 is a perspective view showing an example of the upper body 3 of the work vehicle 1 and the engine 18 mounted on the upper body 3, and Fig. 3 is a perspective view showing the example of the engine 18.

[0027] As shown in Fig. 3, an alternator 63, a water pump 64, and a compressor 65 for an air conditioner are attached to the engine 18 as auxiliary equipment (the compressor 65 is omitted in a machine not equipped with an air conditioner). In this embodiment, the alternator 63, the water pump 64, and a cooling fan (only the fan mounting pulley is shown) 66 are driven by one belt (first belt) 61, and the compressor 65 is driven by another belt (second belt) 62. Note that both the first belt 61 and the second belt 62 are rubber V-belts (the number of ridges may be single or multi) with a resin core wire, which are wound around a crank pulley 60 connected to the crankshaft of the engine 18 to transmit output (rotational force).

[0028] In this embodiment, the first belt 61 is provided with idle pulleys 68 and 69 that set the circumferential position, a tension pulley 67 that applies an appropriate tension, and a tensioner (auto tensioner) 71 that automatically adjusts the tension applied to the first belt 61 via the tension pulley 67 to keep it at an appropriate value. The second belt 62 is provided with a tension pulley 70 that applies an appropriate tension, and a tensioner 72 that manually adjusts the tension applied to the second belt 62 via the tension pulley 70 to keep it at an appropriate value.

[0029] The tensioner (auto tensioner) 71 supports the tension pulley 67 so as to be rotatable and movable, and applies a predetermined biasing force to the tension pulley 67 in the direction in which the first belt 61 is tensioned (the direction of the arrow A). This allows the tension applied to the first belt 61 via the tension pulley 67 to be automatically adjusted and kept at an appropriate value. Note that, as an example of a biasing member that generates the biasing force, a coil spring that is built into the tensioner 71 is used, but the present invention is not limited to this, and other spring members may be used, or a configuration in which the tensioner is mounted externally may be used. On the other hand, the tensioner 72 has a conventional screw-moving type configuration, but an auto tensioner may be used.

[0030] Here, as shown in Figures 1 and 2, the engine room 20 in this embodiment has a main body frame 22 and a cover (not shown) at the bottom, a counterweight 24 at the rear, a partition (not shown) at the front, and covers 53, 54 at the top and on the left and right sides, and is formed as an enclosed space.

[0031] In this embodiment, the counterweight 24 is configured to also serve as the rear wall of the engine room 20 (almost the entire rear wall, but sometimes only a part of the lower half). Due to constraints such as the need to secure the necessary weight in a compact shape, it is difficult to form a large opening (first opening) 51 for maintenance in the counterweight 24 that serves as the rear wall. For this reason (and for other purposes), another opening (second opening) 52 for maintenance is provided in the lower main body frame 22 (however, the main body frame 22 is also a strength member, and a very large opening cannot be formed). In other words, the work vehicle 1 illustrated above is one of the typical configurations in which the replacement work of the belt (first belt 61) must be performed by two people. In the conventional work method, one person fits a socket wrench (the square drive part where the socket is not attached) into the square drive fitting hole 74 of the tensioner 71 from the second opening 52 and rotates the socket wrench to move the tension pulley 67 and maintain a state in which the tension is attenuated. Meanwhile, the other person installs a fixture (conventionally using a screwdriver, pin, or the like) through the first opening 51 to temporarily fix the tension pulley 67 in a moved position (specifically, inserting the fixture into the through hole 75 of the tensioner 71 and engaging it with the engaging portion 73 of the engine 18). As mentioned above, there is a problem that two-person maintenance (belt replacement work) performed in this manner is extremely inefficient.

[0032] This problem can be solved by the maintenance tool 5 according to this embodiment. Here, Fig. 4 is a schematic diagram showing the overall configuration of the maintenance tool 5. Fig. 5 is an enlarged view of a fixing portion 80 of the maintenance tool 5, and Fig. 6 is an enlarged view of a support portion 84 of the maintenance tool 5 (Fig. 6A is an exploded view, and Fig. 6B is an assembly view). Fig. 7 is a perspective view of the maintenance tool 5 attached to a predetermined position on the vehicle body (upper body 3) or the like.

[0033] As shown in Figs. 4 to 7, the maintenance tool 5 includes a fixed part 80 that is detachably attached to a tensioner 71 that biases the tension pulley 67 in the engine 18 to automatically adjust the tension of the belt (first belt 61), and a support part 84 that is detachably attached to the vehicle body (upper body 3). The maintenance tool 5 further includes a pulling part 86 that is movably disposed on the support part 84, and a transmission part 92 that is stretched between the fixed part 80 (specifically, the locking part 82) and the pulling part 86 (specifically, the locking part 87). With this, the fixed part 80 can be moved via the transmission part 92 by moving the pulling part 86, and the tension pulley 67 can be moved in a direction in which the tension of the first belt 61 is attenuated. In addition, the tension pulley 67 can be moved to a predetermined position (a position where a fastener 93, which will be described later, can be engaged with the engaging portion 73 of the engine 18) and maintained in that position, and the fastener 93 can be attached to temporarily fasten the tension pulley 67 in that position. Therefore, it becomes possible for a single person to replace the belt, especially in a work vehicle 1 or the like that has many restrictions regarding openings for maintenance.

[0034] Here, the tension part 86 is, for example, an L-shaped steel, and is provided with a locking part 87 for locking the transmission part 92 near one end (referred to as the "rear end") and a threaded part 88 formed at the other end (referred to as the "front end"), and a nut 89 is screwed onto the threaded part 88. Here, an end face 89a of the nut 89 in the axial direction (specifically, on the transmission part 92 side) is arranged to abut against the support part 84 (specifically, the face 84a on the side not facing the transmission part 92) (a washer 90 may be interposed as appropriate), and the tension part 86 is moved by rotating the nut 89. According to this, the tension part 86 can be moved by simply rotating the nut 89 using a general-purpose tool T such as a spanner or wrench. Therefore, the tension pulley 67 can be moved via the transmission part 92 and the fixed part 80 (details of the operation will be described later). At this time, even if the rotation operation by the general-purpose tool T is stopped, the nut 89 does not rotate, so the tension pulley 67 can be held in the moved position. Therefore, in this state, it is possible to attach the fixing device 93 that temporarily fixes the position of the tension pulley 67. In this manner, the maintenance tool 5 can be realized with an extremely simple configuration.

[0035] Meanwhile, the support portion 84 is provided with a guide groove 85 into which the pulling portion 86 (specifically, the portion near the rear end) enters and guides its movement when the nut 89 is rotated. This makes it possible to prevent the pulling portion 86 from rotating together with the rotation of the nut 89 when moving the pulling portion 86, and to move the pulling portion 86 stably in a predetermined direction.

[0036] Here, the support part 84 is configured to be fixed to the upper body 3 by bolting using the bolt holes 25 for attaching an inspection cover (not shown) provided on the upper body 3 (specifically, the counterweight 24, and the same below) to the upper body 3 in a state where the bracket (not shown) for supporting the inspection cover (not shown) so as to be openable and closable is removed (see FIG. 7, etc.). This allows the support part 84 to be fixed to the upper body 3 by directly using the bolt holes 25 provided on the upper body 3 for attaching the bracket for supporting the inspection cover so as to be openable and closable.

[0037] Next, the transmission part 92 is, for example, configured using a wire, and has locking rings (or hooks, etc.) 92a, 92b at both ends. With this, even if the positional relationship between the drive source (engine 18) and the vehicle body (counterweight 24 to which the bracket is attached) differs for each vehicle due to dimensional tolerances of each part and assembly tolerances between parts, the transmission part 92 can be reliably bridged between the fixed part 80 and the pulling part 86.

[0038] Furthermore, the maintenance tool 5 includes a fixing device 93 that temporarily fixes the position of the tension pulley 67 in a state in which the tension pulley 67 has been moved against the biasing force (i.e., temporarily fixes the position of the tensioner 71 so that no biasing force acts on the tension pulley 67). As an example, the fixing device 93 is a pin (rod-shaped member) made of a metal material. The fixing device 93 is connected to the fixing part 80 using a wire 94 (as an example, a chain, but other wires such as wire or rope may also be used). This makes it possible to prevent the fixing device 93 from being lost, or from being left behind or removed after work.

[0039] Also, the fixed part 80 is provided with, as an example, a square drive 81 that can be fitted into the fitting hole 74 for the square drive of the socket wrench provided in the tensioner 71. This allows the fixed part 80 to be detached from the tensioner 71. Therefore, the fixed part 80 can be fixed to the tensioner 71 by directly using the fitting hole 74 for the square drive of the socket wrench provided in the tensioner 71 to move the tension pulley 67. Note that the "square drive of the socket wrench" refers to a socket mounting part that is substantially rectangular and provided at the tip of the socket wrench. Therefore, the "square drive 81 of the fixed part 80" is formed to have the same shape (particularly the outer diameter) as the "square drive of the socket wrench."

[0040] Next, the operation of moving the tension pulley 67 using the maintenance tool 5, i.e., the operation of reducing the tension of the first belt 61 (i.e., loosening it), in the replacement work of the belt (first belt 61) will be described in detail. Here, Fig. 8 shows the state in which the maintenance tool 5 is attached to a predetermined position (the state before the tension pulley 67 is moved), and Fig. 9 shows the state after the tension pulley 67 has been moved using the maintenance tool 5.

[0041] As shown in Fig. 8, the fixing part 80 is attached to the tensioner 71. Specifically, the square drive 81 of the fixing part 80 is fixed (fitted) into the square drive fitting hole 74 of the tensioner 71. At the same time, the support part 84 is attached to the vehicle body (upper body 3). Specifically, a bracket (not shown) that supports an inspection cover (not shown) of the first opening 51 is removed, and the support part 84 is attached by bolting it into the bolt hole 25 for mounting the bracket.

[0042] 9, the tensioning portion 86 is operated to move the fixed portion 80, thereby moving the tension pulley 67. Specifically, a general-purpose tool (illustrated as a spanner in the figure) T is used to rotate the nut 89 in a predetermined direction. At this time, the locking portion 87 connected to the threaded portion 88 screwed into the nut 89 moves in a predetermined direction (a direction that pulls the transmission portion 92). As a result, the transmission portion 92 locked to the locking portion 87 moves toward the support portion 84. Therefore, the fixed portion 80 and the tension pulley 67 to which the fixed portion 80 is fixed move toward the support portion 84 via the transmission portion 92 (in the direction of arrow B).

[0043] At this time, even if the rotation of the general-purpose tool T is stopped, the nut 89 does not rotate (reverse), so the tension pulley 67 can be maintained in a moved state. Furthermore, in this state, a fixing device 93 can be inserted into the through hole 75 provided in the tensioner 71, and the tip of the fixing device 93 can be locked at a predetermined position (locking portion 73 configured to be able to be locked) of the engine 18. This makes it possible to reliably maintain the tension pulley 67 in an unmoving state.

[0044] By maintaining this state, the worker can easily and safely remove and replace the first belt 61 whose tension has been attenuated (which has become loose) by himself or herself.

[0045] As described above, the maintenance tool according to the present invention makes it possible to move the tension pulley in the tension reduction direction and maintain that state, and also makes it possible to attach a fixture that temporarily fixes the tension pulley in that state. Therefore, it becomes possible for a single person to replace the belt, especially in work vehicles and the like that have many restrictions regarding openings for maintenance.

[0046] The maintenance tool according to the present invention is not limited to application to engines of work vehicles, but can also be applied to other vehicles, as well as to the replacement of belts driven by driving sources other than engines. [Explanation of symbols]

[0047] 1 Vehicle (work vehicle) 3 Body (upper body) 5 Maintenance tools 18 Drive source (engine) 61 Belt 67 Tension pulley 71 Tensioner 80 Fixed part 84 Support part 86 Tension section 92 Transmission section 93 Fixtures

Claims

1. A maintenance tool used when replacing a belt that drives at least one of a fan or an auxiliary device of a drive source of a vehicle, a fixing portion that is detachably attached to a tensioner that rotatably supports a tension pulley that applies tension to the belt; A support part that is detachably attached to a body of the vehicle; A tension portion movably disposed on the support portion; A transmission portion that spans the fixed portion and the tension portion, The tension pulley is configured to move in a direction in which the tension is attenuated by moving the tension portion to move the fixed portion via the transmission portion. A maintenance tool characterized by:

2. The tension portion is provided with a locking portion to which the transmission portion is locked, and a threaded portion is formed at a predetermined position, A nut is screwed onto the threaded portion, and an axial end face of the nut is disposed so as to abut against the support portion, and the tension portion is moved by rotating the nut. The maintenance tool according to claim 1 .

3. The support portion is provided with a guide groove that prevents the tension portion from rotating together with the nut when the nut is rotated and guides the movement in a predetermined direction. The maintenance tool according to claim 2 .

4. The tension pulley is moved in a direction in which the tension is attenuated, and a fixing device is further provided for temporarily fixing the position of the tension pulley in the state where the tension is attenuated, The fixture is attached to the fixed part by a chain, wire, rope, or wire. The maintenance tool according to claim 1 .

5. The fixing portion is provided with a square drive that can be fitted into a fitting hole for a square drive of a socket wrench provided in the tensioner. The maintenance tool according to claim 1 .

6. The support portion is configured to be fixed to the vehicle body by bolting using a bolt hole for attaching the bracket to the vehicle body in a state where the bracket supports an inspection cover provided on the vehicle body so as to be openable and closable is removed. The maintenance tool according to claim 1 .

7. The transmission section is constructed using a wire, and has locking rings or hooks at both ends. The maintenance tool according to claim 1 .

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