Maintenance Tools

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] BACKGROUND 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 using an engine (gasoline engine, diesel engine, etc.) has been widely used. However, recently, a configuration using an electric motor instead of or in addition to the engine is also becoming popular.

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

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

[0006] [Patent Document 1] Patent Publication No. 2021-148110 Summary of the Invention [Problem to be solved by the invention]

[0007] However, since the belts mentioned above are consumables, they need to be replaced periodically or when they deteriorate or become damaged. Belt replacement is typically performed through a maintenance opening in the engine compartment. However, particularly in work vehicles, belt replacement often requires two people due to the constraints of the maintenance opening (such as its location and shape). Specifically, one person uses a rotary tool (such as a socket wrench or open-end wrench) to move the tension pulley and maintain a reduced tension state, while the other person installs a fixture (such as a screwdriver or rod-shaped pin) to temporarily fix the moved tension pulley in place. This makes belt replacement impossible for one person alone, resulting in extremely inefficient work. [Means for solving the problem]

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

[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 components 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 pulling part that is movably arranged on the support part, and a transmission part that spans between the fixed part and the pulling part, and is configured so that by moving the pulling part, the fixed part is moved via the transmission part, and the tension pulley is moved 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 by moving the tensioning part via the transmission part, and a fixture that temporarily fixes the tension pulley in position can be attached while maintaining that state. This makes it possible for a single person to replace the belt.

[0012] Furthermore, it is 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] Preferably, 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 further provided with a fixing device that temporarily fixes the tension pulley in a position after being moved in the direction in which the tension is attenuated, and that the fixing device be tied to the fixed part using a chain, wire, rope, or wire rod.

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

[0016] It is also 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 when the bracket that supports the inspection cover provided on the vehicle body so that it can be opened and closed is removed.

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

[0018] The maintenance tool according to one embodiment can move the tension pulley in the tension reduction direction and maintain that state, and can also attach a fixture that temporarily fixes the tension pulley in that state, making it possible for a single person to replace the belt, especially in work vehicles with many restrictions on openings for maintenance. [Brief explanation 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. [Figure 2] FIG. 2 is a perspective view showing an example of the vehicle body and the drive source of the vehicle shown in FIG. [Figure 3] FIG. 3 is a perspective view showing an example of a drive source for the vehicle of FIG. [Figure 4] FIG. 4 is a perspective view showing an example of a maintenance tool according to an embodiment of the present invention. [Figure 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 of 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 shown in FIG. 4 in an attached 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 INVENTION

[0020] Hereinafter, embodiments 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 ease of explanation, arrows may be used in the drawings to indicate up / down, left / right, and front / rear directions. In all drawings used to explain the embodiments, members having the same functions are denoted by 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, although the following description will be given taking a work vehicle (e.g., a hydraulic excavator) as an example of the vehicle 1 and an engine (e.g., a diesel engine) as an example of the mounted drive source 18, the present invention is not limited to these.

[0022] First, as shown in FIG. 1, the work vehicle (hydraulic excavator) 1 has a vehicle body consisting of a lower body 2 and an upper body 3 disposed on top of the lower body 2 (note that 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 predetermined pressure). The lower body 2 is equipped with a traveling device 10 that enables travel. The upper body 3 is equipped with a driver's cab 16 at the front where an operator sits and operates the vehicle for travel and work. It is also equipped with an engine room 20 at the rear that houses an engine 18, hydraulic pump, etc.

[0024] An example of the traveling device 10 includes a pair of left and right crawlers 26 driven by a traveling hydraulic motor 28. Note that the crawlers 26 may be replaced with tires (not shown).

[0025] An example of the working implement 12 is provided with a blade 30 driven by a hydraulic cylinder 40. An example of the working implement 14 is provided with 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 disposed horizontally in the engine compartment 20 (i.e., with the crankshaft 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, engine 18 is equipped with accessories including an alternator 63, a water pump 64, and an air conditioner compressor 65 (the compressor 65 is omitted in models without an air conditioner). In this embodiment, alternator 63, water pump 64, and a cooling fan (only the fan mounting pulley is shown) 66 are driven by one belt (first belt) 61, and compressor 65 is driven by another belt (second belt) 62. Both first belt 61 and second belt 62 are rubber V-belts (which may have a single or multiple threads) with a resin core wire, which are wound around crank pulley 60 connected to the crankshaft of 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 rotational 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 maintain 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 maintain an appropriate value.

[0029] The tensioner (auto-tensioner) 71 supports the tension pulley 67 so that it can rotate and move, and is configured to apply a predetermined biasing force to the tension pulley 67 in a direction that tensions the first belt 61 (the direction of arrow A). This allows the tension applied to the first belt 61 via the tension pulley 67 to be automatically adjusted and maintained at an appropriate value. Note that, as an example of a biasing member that generates the biasing force, a coil spring that is installed inside the tensioner 71 is used, but this is not limited thereto, and other spring members may be used, or an externally installed member may also be used. Meanwhile, the tensioner 72 has a conventional screw-moving type configuration, but an auto-tensioner may also 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 and 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 doubles as the rear wall of the engine compartment 20 (almost the entire rear wall, but in some cases, only a portion of the lower half). Due to constraints such as the need to maintain a compact shape and sufficient weight, it is difficult to form a large maintenance opening (first opening) 51 in the counterweight 24, which forms the rear wall. For this reason (and for other purposes), a separate maintenance opening (second opening) 52 is provided in the lower main frame 22 (however, the main frame 22 is also a reinforcing member, and a large opening cannot be formed). In other words, the work vehicle 1 illustrated above is a typical example of a configuration in which two people are required to replace the belt (first belt 61). In a conventional work method, one person would insert a socket wrench (the square drive portion without a socket) into the square drive fitting hole 74 of the tensioner 71 through the second opening 52 and rotate the socket wrench to move the tension pulley 67 and maintain a reduced tension state. Meanwhile, the other person installs a fixture (conventionally using a screwdriver, pin, etc.) through the first opening 51 to temporarily fix the tension pulley 67 in place (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, two-person maintenance (belt replacement) performed using this procedure has the problem of being 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. Also, Fig. 5 is an enlarged view of a fixing portion 80 and the like of the maintenance tool 5, and Fig. 6 is an enlarged view of a support portion 84 and the like of the maintenance tool 5 (Fig. 6A is an exploded view, and Fig. 6B is an assembly view). Also, Fig. 7 is a perspective view showing the maintenance tool 5 attached to a predetermined position on the vehicle body (upper body 3) or the like.

[0033] 4 to 7, the maintenance tool 5 includes a fixed part 80 that is detachably attached to a tensioner 71 that biases a 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). As a result, by moving the pulling part 86, the fixed part 80 is moved via the transmission part 92, and the tension pulley 67 can be moved in a direction that attenuates the tension of the first belt 61. Furthermore, the tension pulley 67 can be moved to a predetermined position (a position where a fixing device 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 fixing device 93 can be attached to temporarily fix the tension pulley 67. Therefore, it is possible to perform belt replacement work by one person, especially on work vehicles 1 and the like that have many restrictions regarding openings for maintenance.

[0034] Here, the tensioning portion 86 is, for example, an L-shaped steel bar. The tensioning portion 86 has a locking portion 87 near one end (referred to as the "rear end") to which the transmission portion 92 is locked, and a threaded portion 88 formed at the other end (referred to as the "front end"), onto which a nut 89 is threaded. The axial end face 89a of the nut 89 (specifically, the end face facing the transmission portion 92) is positioned to abut against the support portion 84 (specifically, the face 84a on the side not facing the transmission portion 92) (a washer 90 may be interposed as appropriate). The tensioning portion 86 is moved by rotating the nut 89. This allows the tensioning portion 86 to be moved simply by rotating the nut 89 using a general-purpose tool T, such as a spanner or wrench. Therefore, the tensioning pulley 67 can be moved via the transmission portion 92 and the fixed portion 80 (details of this operation will be described later). Even if the rotational motion of the general-purpose tool T is stopped, the nut 89 does not rotate, so the tensioning 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 way, 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 that allows the pulling portion 86 (specifically, the portion near the rear end) to enter and guide its movement when the nut 89 is rotated. This prevents the pulling portion 86 from rotating together with the rotation of the nut 89 when moving the pulling portion 86, and allows the pulling portion 86 to move stably in a predetermined direction.

[0036] Here, support part 84 is configured to be fixed to upper body 3 by bolting using bolt holes 25 for attaching an inspection cover (not shown) provided on upper body 3 (specifically, counterweight 24, the same below) that supports the inspection cover so that it can be opened and closed, with the bracket (not shown) removed (see FIG. 7, etc.). This allows support part 84 to be fixed to upper body 3 by directly using bolt holes 25 provided in upper body 3 for attaching the bracket that supports the inspection cover so that it can be opened and closed.

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

[0038] Furthermore, the maintenance tool 5 includes a fixing device 93 that temporarily fixes the position of the tension pulley 67 while the tension pulley 67 is 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 prevents the fixing device 93 from being lost, or from being forgotten to be removed or left behind after work.

[0039] Furthermore, the fixed part 80 is provided with, as an example, a square drive 81 that can fit into the socket wrench square drive fitting hole 74 provided in the tensioner 71. This makes it detachable from the tensioner 71. Therefore, the fixed part 80 can be fixed to the tensioner 71 by directly utilizing the socket wrench square drive fitting hole 74 provided in the tensioner 71 to move the tension pulley 67. Note that the "square drive of the socket wrench" refers to a substantially rectangular parallelepiped socket attachment part 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 Figure 8, the fixed part 80 is attached to the tensioner 71. Specifically, the square drive 81 of the fixed 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, the bracket (not shown) that supports the 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 attaching the bracket.

[0042] Next, as shown in Figure 9, the tension pulley 67 is moved by operating the tensioning portion 86 to move the fixed portion 80. Specifically, a general-purpose tool (illustrated as a wrench in the figure) T is used to rotate the nut 89 in a predetermined direction. At this time, the locking portion 87, which is continuous with the threaded portion 88 that is threadedly engaged with the nut 89, moves in a predetermined direction (a direction that pulls the transmission portion 92). As a result, the transmission portion 92, which is locked by 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 will not rotate (reverse), so the tension pulley 67 can be maintained in a moved state. Furthermore, in this state, a fastener 93 can be inserted into the through-hole 75 provided in the tensioner 71, and the tip of the fastener 93 can be locked at a predetermined position (locking portion 73 configured to be lockable) on the engine 18. This allows the tension pulley 67 to be reliably maintained 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.

[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 to attach a fixture that temporarily fixes the tension pulley in that state. Therefore, it is possible to replace the belt by one person, especially in work vehicles and the like that have many restrictions on 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 drive 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 Tensile 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 auxiliary device of a drive source of a vehicle, a fixing portion 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 tensioning portion movably disposed on the support portion; a transmission part that spans the fixed part and the tension part, The tension pulley is configured to move in a direction in which the tension is attenuated by moving the tensioning portion, thereby moving 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 the 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 further provided with a fixing device that temporarily fixes the tension pulley in a state where the tension pulley is moved in a direction in which the tension is attenuated, The fixture is connected to the fixed part by a chain, wire, rope, or wire rod. The maintenance tool according to claim 1 ,

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

6. The transmission part is made of a wire and has locking rings or hooks on both ends. The maintenance tool according to claim 1 ,

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