Belt attachment method

Abstract

The present invention relates to a belt attachment method in which a circumferentially extendable belt is looped around at least four pulleys laid out in the following order: first pulley, second pulley, third pulley, and fourth pulley. The belt attachment method comprises: a step for passing the belt through an opening and into a space on the inner circumferential side of a circumferential portion of an auxiliary jig having said opening and said circumferential portion, the space on the inner circumferential side of the circumferential portion being located on a running line of the belt between the first pulley and the second pulley; a step for attaching, to the first pulley, an attaching jig comprising a pressing portion disposed to face the outer circumference of the first pulley and a winding portion that is pressed against the first pulley by the tension of the belt; a step for passing the belt along the winding portion and between the outer circumference of the first pulley and the pressing portion, and temporarily hanging the belt on the first pulley in such a state that the inner circumferential surface of the belt is facing a lateral surface of the first pulley; and step for rotating the first pulley in a state in which the belt is looped around the second pulley, the third pulley, and the fourth pulley and in which the belt is temporarily hung on the first pulley.

Description

How to attach the belt

[0001] The present invention relates to a method for installing a circumferentially stretchable belt between a plurality of pulleys, in which the belt is wound around the pulleys using a belt installation jig.

[0002] For example, there is a layout of a belt transmission mechanism in which the distances between the axes of the multiple pulleys to be mounted are all fixed and no tensioning mechanism such as a tension pulley or tensioner is used. In a belt transmission mechanism with such a layout, in order to reliably transmit power between the pulleys, the belt circumference is made shorter than the layout circumference between the multiple pulleys to be mounted, so that a strong tension is applied to the belt.

[0003] The task of attaching a belt between such a plurality of pulleys, which has a circumferential length shorter than the layout circumferential length between the plurality of pulleys, can be time-consuming because it requires a force to resist the tension of the belt.

[0004] Therefore, as a method for attaching a belt having a circumference shorter than the layout circumference between multiple pulleys as described above, as disclosed in Patent Documents 1 and 2, a stretching attachment method using an attachment jig is used, in which the belt is first wound around one pulley, leaving one pulley as the last, and then tensioning the belt wound around the other pulleys using an attachment jig while stretching it by about 1 to 5%, while rotating the last pulley to fit the belt around the outer surface of that pulley.

[0005] Japanese Patent No. 7384857 Japanese Patent No. 6145145

[0006] However, these methods are primarily intended for winding a belt around a layout consisting of two or three pulleys. When winding a belt around a layout consisting of four or more pulleys, the distance between the pulleys is often short due to layout constraints such as a narrow layout. When the distance between the pulleys is short, the stretched mounting method using the mounting jig described above causes significant twisting and tilt of the belt between the pulley onto which the belt is first wound and the pulley onto which the belt is last wound, which can cause the belt to slip from the pulley onto which it was first wound, resulting in the belt coming off.

[0007] Therefore, an object of the present invention is to provide a belt mounting method that can prevent the belt from slipping off the ribs of the belt and coming off the pulley that it is wrapped around first when the belt is stretchable in the circumferential direction and mounted between at least four pulleys.

[0008] In order to solve the above problems, the present invention provides a belt installation method for winding a belt stretchable in a circumferential direction around at least four pulleys laid out in the order of a first pulley, a second pulley, a third pulley, and a fourth pulley, the method comprising the steps of: passing the belt from the opening of an auxiliary jig having an opening and a circumferential portion, the space on the inner periphery of the circumferential portion being arranged on the running path of the belt between the first pulley and the second pulley, into the space on the inner periphery of the circumferential portion; attaching to the first pulley an installation jig having a pressing portion arranged to face the outer periphery of the first pulley and a winding portion that is pressed against the first pulley by the tension of the belt; aligning the belt along the winding portion and passing it between the outer periphery of the first pulley and the pressing portion, and temporarily winding the belt around the first pulley with the inner periphery of the belt facing the side of the first pulley; and rotating the first pulley with the belt wound around the second pulley, the third pulley, and the fourth pulley and the belt temporarily wound around the first pulley.

[0009] According to the above method, when the first pulley is rotated and the belt is wound around the first pulley, the belt is prevented from twisting by the holding portion of the mounting jig on the fourth pulley side, and the belt is prevented from twisting by the auxiliary jig on the second pulley side. This prevents the belt from slipping at the fourth pulley and the second pulley. Furthermore, if the space on the inner circumferential side of the auxiliary jig's peripheral portion is positioned outward from the outer circumferential surface of the belt on the running line, when the belt is wound around the first pulley, the inner circumferential surface of the belt will not face the side of the first pulley, but the side of the belt will face the side of the first pulley. As a result, when the first pulley is rotated, the belt may ride up on the second pulley due to the rib slippage toward the front side of the second pulley, causing the belt to come off the second pulley. On the other hand, if the space on the inner periphery of the circumferential portion of the auxiliary jig is positioned inside the inner periphery of the belt on the running line, the belt will be twisted excessively when wrapped around the outer periphery of the first pulley, and the inner periphery of the belt will not face the side of the first pulley. As a result, when the first pulley is rotated, the belt may ride up due to rib misalignment toward the back of the second pulley, causing the belt to come off the second pulley. Therefore, by positioning the space on the inner periphery of the circumferential portion of the auxiliary jig on the running line of the belt between the first and second pulleys, when the belt is passed through the space on the inner periphery of the circumferential portion of the auxiliary jig, the belt is kept on the running line, and therefore, when the belt is wrapped around the outer periphery of the first pulley, the belt will be twisted appropriately so that the inner periphery of the belt faces the side of the first pulley. As a result, when the first pulley is rotated, the belt does not slip off the ribs of the second pulley, preventing the belt from coming off the second pulley. Note that the rear side of the second pulley is the side where the crankshaft is inserted into the center of the first pulley, i.e., the rear side of the paper on which the layout in Figure 1 is shown. The front side of the second pulley is the side where the rotary tool is attached to the center of the first pulley, i.e., the front side of the paper on which the layout in Figure 1 is shown.

[0010] In the belt mounting method of the present invention, the inner periphery of the circumferential portion of the auxiliary jig may have a curved portion that comes into contact with the belt.

[0011] According to the above method, the auxiliary tool can prevent excessive force from being applied to a part of the belt when restricting the twist of the belt.

[0012] Furthermore, in the above-described belt mounting method of the present invention, the fourth pulley may be a back pulley with which the outer peripheral surface of the belt contacts, and in the step of rotating the first pulley, the direction in which the first pulley is rotated may be a direction from the fourth pulley toward the second pulley.

[0013] According to the above method, the belt between the first pulley and the fourth pulley is twisted, causing the belt to slip sideways on the fourth pulley, which is the back pulley, causing the belt ribs to shift on the third pulley, and preventing the belt from riding up on the third pulley.

[0014] Furthermore, in the step of rotating the first pulley in the above-described belt mounting method, if the direction in which the first pulley is rotated is a direction in which a mounting bolt that mounts the first pulley to the layout is loosened, the first pulley may be rotated by engaging an engaging portion of a rotating plate having an engaging portion and a mating portion that can be mated with a rotary tool with the side of the first pulley, then mating the rotary tool with the mating portion, and rotating the rotary tool in the direction in which the mounting bolt is loosened.

[0015] Typically, the first pulley is attached to the layout by tightening a mounting bolt that can be fitted with a rotary tool such as a torque wrench or wrench. However, when attaching a belt to the first pulley, if the first pulley needs to be rotated in a direction to loosen the mounting bolt, engaging the rotary tool with the mounting bolt and rotating the first pulley in the direction to loosen the mounting bolt will cause the first pulley to come off the layout. Therefore, by engaging the engaging portion of the rotating plate with the side of the first pulley, engaging the rotary tool with the engaged portion, and rotating the rotary tool in the direction to loosen the mounting bolt, the first pulley can be rotated in the direction to loosen the mounting bolt without coming off the layout.

[0016] To provide a belt mounting method capable of preventing the belt from slipping off the ribs of the belt from the pulley on which it is first wound and coming off when the belt stretchable in the circumferential direction is mounted between four or more pulleys.

[0017] FIG. 1 is an explanatory diagram of the layout of the accessory drive unit according to the present embodiment. FIG. 2 is an explanatory diagram of a crank pulley according to the present embodiment. FIG. 3 is a perspective view of the mounting jig according to the present embodiment. FIG. 4 is a six-sided view of the mounting jig according to the present embodiment. FIG. 5 is an explanatory diagram of an auxiliary jig according to the present embodiment. FIG. 6 is an explanatory diagram of a rotating plate according to the present embodiment. FIG. 7 is an explanatory diagram of step (b) of the belt mounting method according to the present embodiment. FIG. 8 is an explanatory diagram of step (c) of the belt mounting method according to the present embodiment. FIG. 9 is an explanatory diagram of step (d) of the belt mounting method according to the present embodiment. FIG. 10 is an explanatory diagram of steps (e) and (f) of the belt mounting method according to the present embodiment. FIG. 11 is an explanatory diagram of step (f) of the belt mounting method according to the present embodiment. FIG. 12 is an explanatory diagram of the mounting position of the auxiliary jig according to the present embodiment.

[0018] (Embodiment) In this embodiment, a belt mounting method will be described in which a V-ribbed belt 5 is wound around a four-shaft accessory drive unit 10 of an automobile engine.

[0019] 1 , a V-ribbed belt 5 stretchable in the circumferential direction is wound around a crank pulley 1 connected to the engine power drive shaft, an air conditioner compressor pulley 2 connected to the rotating shaft of an air conditioner compressor, an alternator pulley 3 connected to the rotating shaft of an alternator, and a water pump pulley 4 connected to the rotating shaft of a water pump. The V-ribbed belt 5 wound around the air conditioner compressor pulley 2, the alternator pulley 3, and the water pump pulley 4 is then wound around the crank pulley 1. In this embodiment, the center distances between the crank pulley 1, the air conditioner compressor pulley 2, the alternator pulley 3, and the water pump pulley 4 are fixed and unchangeable. Furthermore, an auto-tensioner, which is a tension applying means for applying tension to the V-ribbed belt 5, is not installed.

[0020] (Crank pulley 1) The crank pulley 1 has a pulley groove 11 formed on its outer periphery that can mate with a rib 51 formed on the inner periphery of the V-ribbed belt 5. A crankshaft of an engine or the like is inserted into a boss 12 formed in the center of the crank pulley 1. The crank pulley 1 is rotatably attached to the accessory drive unit 10 by fastening a mounting bolt to the boss 12.

[0021] Furthermore, two elongated holes 13 and 14 are formed on the side surface of the crank pulley 1, straddling the boss portion 12 at the center of the crank pulley 1, on both sides of the boss portion 12. As shown in FIG. 2 , the central portion of the elongated hole 13 is formed to have approximately the same size as the outer diameter of the locking portion 912 of the engaging portion 91 of the rotating plate 9, and both ends of the elongated hole 13 are formed to have approximately the same size as the outer diameter of the support portion 911 of the engaging portion 91 of the rotating plate 9, which is smaller than the outer diameter of the locking portion 912. The elongated hole 14 is also similar to the elongated hole 13. As a result, the engaging portions 91 and 92 of the rotating plate 9, which will be described later, engage with the elongated holes 13 and 14 on the side surface of the crank pulley 1. A detailed description will be given later.

[0022] A flange portion 15 on the side surface of the crank pulley 1 is formed with a recess 16 into which a mounting jig 7 (described later) is fitted.

[0023] (Air conditioner compressor pulley 2) The air conditioner compressor pulley 2 has pulley grooves 21 formed on its outer periphery that can mate with ribs 51 formed on the inner circumferential surface of the V-ribbed belt 5. A shaft that operates in conjunction with the air conditioner compressor is inserted into a boss portion 22 formed in the center of the air conditioner compressor pulley 2. The air conditioner compressor pulley 2 is rotatably attached to the accessory drive unit 10 by fastening a mounting bolt to the boss portion 22.

[0024] (Alternator pulley 3) The alternator pulley 3 has pulley grooves 31 formed on its outer periphery that can mate with ribs 51 formed on the inner periphery of the V-ribbed belt 5. A shaft that moves in conjunction with the alternator is inserted into a boss 32 formed in the center of the alternator pulley 3. The alternator pulley 3 is rotatably attached to the accessory drive unit 10 by fastening a mounting bolt to the boss 32.

[0025] (Water Pump Pulley 4) The water pump pulley 4 is a back pulley with which the outer peripheral surface of the V-ribbed belt 5 contacts. That is, the outer peripheral surface of the V-ribbed belt 5 contacts the outer periphery of the water pump pulley 4 when the V-ribbed belt 5 is bent so that its outer peripheral surface faces inward, i.e., in a reverse bent state. The outer periphery of the water pump pulley 4 does not have any pulley grooves or flanges, and is flat. A shaft connected to the water pump is inserted into a boss portion 42 formed in the center of the water pump pulley 4. The water pump pulley 4 is rotatably attached to the accessory drive unit 10 by fastening a mounting bolt to the boss portion 42. The use of a back pulley increases the winding angle of the V-ribbed belt 5 wound around the pulley adjacent to the back pulley, thereby improving power transmission efficiency. That is, slippage and the like can be prevented. In this embodiment, the pulleys adjacent to the back pulley are the crank pulley 1 and the alternator pulley 3.

[0026] (V-ribbed belt 5) The V-ribbed belt 5 is a so-called low modulus belt that is slightly stretchable in its circumferential direction. A low modulus belt has a relatively low elastic modulus due to the use of polyamide fiber for the core wire, and is less susceptible to sudden drops in tension compared to so-called high modulus belts, which are belts with a high elastic modulus. The inner peripheral surface of the V-ribbed belt 5 is formed with ribs 51 that can be engaged with pulley grooves 11 of the crank pulley 1, etc. The outer peripheral surface of the V-ribbed belt 5 has a flat shape.

[0027] Furthermore, arrow V in FIG. 1 indicates the running direction of the V-ribbed belt 5, and the rotation direction of the crank pulley 1 when the V-ribbed belt 5 runs in this running direction is defined as leftward direction A, and the rotation direction opposite to this leftward direction A is defined as rightward direction.

[0028] (Configuration of mounting jig 7) As shown in Figures 3 and 4, the mounting jig 7 used in the belt mounting method of this embodiment includes a pressing portion 71 arranged to face the outer periphery of the crank pulley 1, and a winding portion 72 that is pressed against the crank pulley 1 by the tension of the V-ribbed belt 5 when the V-ribbed belt 5 is wound around the crank pulley 1, i.e., when temporarily wound.

[0029] The pressing portion 71 is shaped to protrude from the winding portion 72 onto the outer periphery of the crank pulley 1 so that a gap approximately equal to or slightly larger than the thickness of the V-ribbed belt 5 is formed between the inner surface of the pressing portion 71 and the outer periphery of the crank pulley 1.

[0030] The winding portion 72 has an arc shape so as to fit along the flange portion 15 on the side surface of the crank pulley 1, and a protrusion 73 is formed on the inside of the winding portion 72, which corresponds to the recess 16 formed in the flange portion 15 on the side surface of the crank pulley 1. In addition, a recess 74 corresponding to the protrusion 73 is formed on the outside of the winding portion 72.

[0031] The material of the mounting jig 7 in this embodiment is resin, but it may also be iron or stainless steel.

[0032] (Auxiliary Jig 8) In this embodiment, the auxiliary jig 8 is a gourd-shaped carabiner having an opening 81 and a circumferential portion 82, as shown in FIG.

[0033] The opening 81 only needs to be large enough to allow the V-ribbed belt 5 to pass through, and may remain open or may further have an openable / closable closing member.

[0034] The circumferential portion 82 may have a shape such as a circle, an ellipse, a pear, a square, or a triangle as long as the space 83 on the inner periphery is large enough to hold the V-ribbed belt 5 in the width direction, but it is preferable that the inner periphery of the circumferential portion 82 has a curved shape at the portion that comes into contact with the V-ribbed belt 5. In this way, because the inner periphery of the circumferential portion 82 of the auxiliary jig 8 has a curved shape, it is possible to prevent excessive force from being applied to parts of the V-ribbed belt 5 when the auxiliary jig 8 restricts twisting of the V-ribbed belt 5 when the V-ribbed belt 5 is wound around the accessory drive unit 10.

[0035] 13 , the auxiliary jig 8 is attached to the accessory drive unit 10 with screws or the like so that the space 83 on the inner circumferential side of the circumferential portion 82 is positioned on the running line L of the V-ribbed belt 5 between the crank pulley 1 and the air conditioner compressor pulley 2 when the V-ribbed belt 5 runs in the accessory drive unit 10, more preferably with the V-ribbed belt 5 not in contact with the circumferential portion 82. The auxiliary jig 8 is removed after the installation of the V-ribbed belt 5 to the accessory drive unit 10 is complete.

[0036] (Rotating plate 9) As shown in Figure 6, the rotating plate 9 comprises a rectangular plate 94 with chamfered corners, a hexagonal nut 93 as a mating part fixed to the center of the surface of the plate 94, and engaging parts 91 and 92 attached to both ends of the back surface of the plate 94.

[0037] The shape of the hexagonal nut 93 is not limited as long as it can be fitted with a rotary tool such as a torque wrench 99 or a wrench. The engaging portion 91 (92) has a support portion 911 (921) press-fitted into holes 95 (96) formed on both ends of the plate 94, and a locking portion 912 (922) provided at the tip of the support portion 911 (921) and having an outer diameter larger than the support portion 911 (921). The engaging portions 91 and 92 of this rotating plate 9 are engaged with elongated holes 13 and 14 on the side of the crank pulley 1.

[0038] (Belt Mounting Method) Next, a belt mounting method for winding the V-ribbed belt 5 around the accessory drive unit 10 will be described with reference to FIGS.

[0039] <Step (a)> As shown in Figure 13, the auxiliary jig 8 is attached to the accessory drive unit 10 in advance using screws or the like so that the space 83 on the inner circumferential side of the circumferential portion 82 is positioned on the running line L of the V-ribbed belt 5 between the crank pulley 1 and the air conditioner compressor pulley 2.

[0040] <Step (b)> Next, the V-ribbed belt 5 is wound around the air conditioner compressor pulley 2 and the alternator pulley 3. Then, as shown in Figure 7, while holding down the wound V-ribbed belt 5 with a hand to prevent it from lifting up, the V-ribbed belt 5 is passed through the opening 81 of the auxiliary jig 8 into the space 83 on the inner periphery of the circumferential portion 82 so that the back surface of the V-ribbed belt 5 faces the viewer. The back surface of the V-ribbed belt 5 is the so-called outer periphery of the V-ribbed belt 5. Here, since the position of the space 83 on the inner periphery of the circumferential portion 82 of the auxiliary jig 8 is positioned on the running line L of the V-ribbed belt 5 between the crank pulley 1 and the air conditioner compressor pulley 2, when the V-ribbed belt 5 is passed through the space 83 on the inner periphery of the circumferential portion 82 of the auxiliary jig 8, the V-ribbed belt 5 is held on the running line L in an appropriately twisted state so that the outer periphery faces the viewer.

[0041] <Step (c)> Next, as shown in Figure 8, the mounting jig 7 is mounted to the crank pulley 1 by fitting the protrusion 73 of the mounting jig 7 into the recess 16 formed in the flange portion 15 on the side of the crank pulley 1. At this time, the pressing portion 71 is positioned to face the outer periphery of the crank pulley 1, and a gap that is approximately the same as or slightly larger than the thickness of the V-ribbed belt 5 is formed between the inner surface of the pressing portion 71 and the outer periphery of the crank pulley 1. In addition, the winding portion 72 covers the edge of the flange portion 15 on the side of the crank pulley 1, which is the portion on which the V-ribbed belt 5 is temporarily wound.

[0042] 9 , the V-ribbed belt 5 is passed between the outer periphery of the crank pulley 1 and the presser portion 71 along the recess 74 of the winding portion 72 of the mounting jig 7, and temporarily wound around the crank pulley 1 with the inner peripheral surface of the V-ribbed belt 5 facing the side surface of the crank pulley 1. At this time, the V-ribbed belt 5 is also wound around the water pump pulley 4 in a bent state so that the outer peripheral surface of the V-ribbed belt 5 faces the inner peripheral side, i.e., in a reverse bent state.

[0043] 10 , the locking portions 912, 922 of the engaging portions 91, 92 of the rotating plate 9 are inserted into central portions of the elongated holes 13, 14 formed in the side surface of the crank pulley 1, the central portions having approximately the same size as the outer diameter of the locking portions 912, 922, and the rotating plate 9 is turned in the left direction A so that the locking portions 912, 922 of the engaging portions 91, 92 are locked to both ends of the elongated holes 13, 14 which have smaller outer diameters than the locking portions 912, 922, and the engaging portions 91, 92 are engaged with the side surface of the crank pulley 1. In this way, the rotating plate 9 is attached to the side surface of the crank pulley 1.

[0044] Typically, the crank pulley 1 is attached to the accessory drive unit 10 by fastening a mounting bolt that can be engaged with a torque wrench 99 or the like to the boss portion 12. However, when attaching the V-ribbed belt 5 to the crank pulley 1 or the like, if it is necessary to rotate the crank pulley 1 in the left direction A, which is the direction in which the mounting bolt is loosened, engaging a torque wrench 99 or the like with the mounting bolt and rotating the crank pulley 1 in the direction in which the mounting bolt is loosened may result in the crank pulley 1 coming off the accessory drive unit 10. Therefore, after attaching the rotating plate 9 to the side of the crank pulley 1, a torque wrench 99 is engaged with the hexagonal nut 93 and the torque wrench 99 or the like is rotated in the direction in which the mounting bolt is loosened, so that the crank pulley 1 can be rotated in the direction in which the mounting bolt is loosened without coming off the accessory drive unit 10.

[0045] <Step (f)> As shown in FIG. 10 , with the V-ribbed belt 5 wound around the air conditioner compressor pulley 2, the alternator pulley 3, and the water pump pulley 4, and the V-ribbed belt 5 temporarily wound around the crank pulley 1, a torque wrench 99 or a wrench or the like is engaged with the hexagonal nut 93 of the rotating plate 9, and the torque wrench 99 is rotated in the left direction A to rotate the crank pulley 1 in the left direction A.

[0046] In this embodiment, the crank pulley 1 rotates in the leftward direction A, which is the direction from the water pump pulley 4 (the rear pulley) toward the air conditioner compressor pulley 2. If the crank pulley 1 were rotated rightward, which is the direction from the air conditioner compressor pulley 2 toward the water pump pulley 4, the V-ribbed belt 5 between the crank pulley 1 and the water pump pulley 4 would twist, causing the V-ribbed belt 5 to skid on the water pump pulley 4 (the rear pulley), which would cause the ribs of the V-ribbed belt 5 to shift on the alternator pulley 3, and the V-ribbed belt 5 would ride up on the alternator pulley 3. Therefore, by rotating the crank pulley 1 in the leftward direction A, the above-mentioned problems can be prevented.

[0047] The crank pulley 1 is rotated in the left direction A from the state shown in Figure 10 to the state shown in Figure 11. As a result, high tension is generated in the V-ribbed belt 5 as it is stretched. Because the V-ribbed belt 5 crosses over the winding portion 72 of the mounting jig 7, this tension acts as a pressing force that presses the mounting jig 7 against the crank pulley 1, and the mounting jig 7 and the crank pulley 1 are more firmly fixed together.

[0048] Continuing, when the crank pulley 1 is rotated in the left direction A from the state shown in Figure 11 to the state shown in Figure 12, the V-ribbed belt 5 wound around the winding portion 72 of the mounting jig 7 moves onto the outer periphery of the crank pulley 1. During this movement, the mounting jig 7 comes off the outer periphery of the crank pulley 1.

[0049] As described above, when the crank pulley 1 is rotated and the V-ribbed belt 5 is wound around the outer periphery of the crank pulley 1, the presser portion 71 of the mounting jig 7 prevents the V-ribbed belt 5 from twisting on the water pump pulley 4 side of the V-ribbed belt 5. On the other hand, the auxiliary jig 8 prevents the V-ribbed belt 5 from twisting on the air conditioner compressor pulley 2 side of the V-ribbed belt 5. This prevents the ribs of the V-ribbed belt 5 from misaligning on the water pump pulley 4 and the air conditioner compressor pulley 2.

[0050] 13 , in the above-described mounting method, the space 83 on the inner circumferential side of the circumferential portion 82 of the auxiliary jig 8 is positioned on the running line L of the V-ribbed belt 5 between the crank pulley 1 and the air conditioner compressor pulley 2. If the space 83 on the inner circumferential side of the circumferential portion 82 of the auxiliary jig 8 were positioned outward from the outer circumferential surface of the V-ribbed belt 5 on the running line L, when the V-ribbed belt 5 is wound around the outer periphery of the crank pulley 1, the inner circumferential surface of the V-ribbed belt 5 would not face the side of the crank pulley 1, but the side of the V-ribbed belt 5 would face the side of the crank pulley 1. As a result, when the crank pulley 1 is rotated, the V-ribbed belt 5 may ride up due to rib misalignment toward the front side of the air conditioner compressor pulley 2, causing the V-ribbed belt 5 to come off the air conditioner compressor pulley 2. On the other hand, if the position of the space 83 on the inner periphery of the circumferential portion 82 of the auxiliary jig 8 is located inside the inner periphery of the V-ribbed belt 5 on the running line L, the V-ribbed belt 5 will be twisted excessively when winding the V-ribbed belt 5 around the outer periphery of the crank pulley 1, and the inner periphery of the V-ribbed belt 5 will no longer face the side of the crank pulley 1. As a result, when the crank pulley 1 is rotated, the V-ribbed belt 5 will ride up due to rib displacement toward the back side of the air conditioner compressor pulley 2, and the V-ribbed belt 5 may come off the air conditioner compressor pulley 2. Therefore, by positioning the space 83 on the inner circumferential side of the circumferential portion 82 of the auxiliary jig 8 on the running line L of the V-ribbed belt 5 between the crank pulley 1 and the air conditioner compressor pulley 2, when the V-ribbed belt 5 is passed through the space 83 on the inner circumferential side of the circumferential portion 82 of the auxiliary jig 8, the V-ribbed belt 5 is held on the running line L between the crank pulley 1 and the air conditioner compressor pulley 2. Therefore, when the V-ribbed belt 5 is wound around the outer periphery of the crank pulley 1, the V-ribbed belt 5 is twisted appropriately so that the inner circumferential surface of the V-ribbed belt 5 faces the side surface of the crank pulley 1. As a result, when the crank pulley 1 is rotated, the V-ribbed belt 5 does not slip at the air conditioner compressor pulley 2, and it is possible to prevent the V-ribbed belt 5 from coming off the air conditioner compressor pulley 2.

[0051] <Step (g)> Finally, the mounting jig 7 is withdrawn, the auxiliary jig 8 is removed from the accessory drive unit 10 , and the rotating plate 9 is removed from the crank pulley 1 .

[0052] By going through the above procedure, the V-ribbed belt 5 can be wound around the accessory drive unit 10 consisting of the crank pulley 1, air conditioner compressor pulley 2, alternator pulley 3, and water pump pulley 4.

[0053] (Other Embodiments) In the above embodiment, a belt mounting method has been described in which the V-ribbed belt 5 is wound around the accessory drive unit 10 having four pulleys, namely, the crank pulley 1, the air conditioner compressor pulley 2, the alternator pulley 3, and the water pump pulley 4. However, the layout of the accessory drive unit 10 may also include five or more pulleys.

[0054] Furthermore, in the above step (d), the V-ribbed belt 5 may be passed between the outer periphery of the crank pulley 1 and the pressing portion 71, and then temporarily wound around the crank pulley 1 with the inner periphery of the V-ribbed belt 5 facing the side of the crank pulley 1 along the recess 74 of the winding portion 72.

[0055] The order of the above steps (a) to (e) may be changed as needed. For example, the V-ribbed belt 5 may be wound around the accessory drive unit 10 in the order of steps (a), (c), (d), (b), (e), (f), and (g).

[0056] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be implemented in various modifications as long as they are within the scope of the claims. This application is based on Japanese Patent Application No. 2024-072990 filed on April 26, 2024 and Japanese Patent Application No. 2025-065520 filed on April 11, 2025, the contents of which are incorporated herein by reference.

[0057] REFERENCE SIGNS LIST 1 crank pulley (first pulley) 2 air conditioner compressor pulley (second pulley) 3 alternator pulley (third pulley) 4 water pump pulley (fourth pulley) 5 V-ribbed belt 7 mounting jig 71 holding portion 72 winding portion 8 auxiliary jig 81 opening 82 peripheral portion 83 space 9 rotating plate 91, 92 engaging portion 93 hexagonal nut (engaged portion) 10 accessory drive unit L running line

Claims

1. A method of attaching a belt, in which a belt stretchable in the circumferential direction is wound around at least four pulleys arranged in the order of a first pulley, a second pulley, a third pulley, and a fourth pulley, comprising the steps of: passing the belt from the opening of an auxiliary jig having a circumferential portion and a circumferential portion, the space on the inner periphery of which is arranged on the running path of the belt between the first pulley and the second pulley, into the space on the inner periphery of the circumferential portion; attaching an attachment jig to the first pulley, the attachment jig having a pressing portion arranged to face the outer periphery of the first pulley and a winding portion that is pressed against the first pulley by the tension of the belt; aligning the belt along the winding portion and passing it between the outer periphery of the first pulley and the pressing portion, and temporarily winding the belt around the first pulley with the inner periphery of the belt facing the side of the first pulley; and rotating the first pulley with the belt wound around the second pulley, the third pulley, and the fourth pulley and the belt temporarily wound around the first pulley.

2. The belt mounting method according to claim 1, wherein the inner periphery of the peripheral portion of the auxiliary jig has a curved shape at the portion that comes into contact with the belt.

3. A method of installing a belt as described in claim 1 or 2, wherein the fourth pulley is a back pulley with which the outer surface of the belt comes into contact, and in the step of rotating the first pulley, the direction in which the first pulley is rotated is from the fourth pulley toward the second pulley.

4. A method for installing a belt as described in any one of claims 1 to 3, wherein in the step of rotating the first pulley, if the direction in which the first pulley is rotated is a direction in which a mounting bolt attaching the first pulley to the layout is loosened, the method involves engaging an engaging portion of a rotating plate having an engaging portion and a mating portion capable of mating with a rotary tool with the side of the first pulley, then mating the rotary tool with the mating portion, and rotating the rotary tool in the direction in which the mounting bolt is loosened, thereby rotating the first pulley.

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