How to attach the belt

Abstract

To prevent an extensible belt from coming off from the pulley on which it is first wound when the belt is fitted between four or more pulleys. [Solution] When winding a circumferentially stretchable V-ribbed belt 5 around an accessory drive unit 10, the belt installation method includes the steps of: passing the V-ribbed belt 5 from an opening 81 of an auxiliary jig 8 arranged on the running line L of the V-ribbed belt 5 between a crank pulley 1 and an air conditioner compressor pulley 2 into a space 83 in a circumferential portion 82; attaching an installation jig 7 to the crank pulley 1; aligning the V-ribbed belt 5 along the winding portion 72 and passing it between the outer periphery of the crank pulley 1 and a pressure portion 71 to temporarily wrap it around the crank pulley 1; and rotating the crank pulley 1 with the V-ribbed belt 5 wound around the air conditioner compressor pulley 2, alternator pulley 3, and water pump pulley 4 and the V-ribbed belt 5 temporarily wrapped around the crank pulley 1.

Description

[Technical Field]

[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. [Background technology]

[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 stretch-mounting method using an attachment jig is used, in which the belt is first wound around the other pulleys, leaving one pulley as the last, and then tensioning the belt wound around the other pulleys by stretching it by about 1 to 5% using an attachment jig, while rotating the last pulley to fit the belt around the outer surface of that pulley. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7384857 [Patent Document 2] Patent No. 6145145 Summary of the Invention [Problem to be solved by the invention]

[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 installation 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 installing a circumferentially stretchable belt between at least four pulleys. [Means for solving the problem]

[0008] In order to solve the above problem, the present invention provides a belt mounting method in which a belt that is stretchable in a circumferential direction is wound around at least four pulleys that are laid out in the order of a first pulley, a second pulley, a third pulley, and a fourth pulley, an auxiliary jig having an opening and a circumferential portion, the space on the inner circumferential side of the circumferential portion being disposed on a running line of the belt between the first pulley and the second pulley; and a step of passing the belt from the opening into the space on the inner circumferential side of the circumferential portion of the auxiliary jig. a step of attaching an attachment jig to the first pulley, the attachment jig including a pressing portion disposed to face an outer periphery of the first pulley and a winding portion that is pressed against the first pulley by the tension of the belt; a step of guiding 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 in a state where an inner circumferential surface of the belt faces a side surface of 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, and rotating the first pulley.

[0009] According to the above method, when the first pulley is rotated and the belt is wound around the outer periphery of the first pulley, the belt is prevented from twisting by the pressing portion of the mounting jig on the fourth pulley side of the belt, and the belt is prevented from twisting by the auxiliary jig on the second pulley side of the belt, thereby preventing rib misalignment of the belt on the fourth pulley and on the second pulley. Furthermore, if the space on the inner periphery of the peripheral portion of the auxiliary jig is positioned outside the outer periphery of the belt on the running line, when the belt is wound around the outer periphery of the first pulley, the inner periphery 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 due to rib misalignment 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 auxiliary jig is located 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 no longer face the side of the first pulley. As a result, when the first pulley is rotated, the belt will ride up due to the rib shifting toward the back side of the second pulley, and the belt may come off the second pulley. Therefore, by positioning the space on the inner circumferential side 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 circumferential side of the circumferential portion of the auxiliary jig, the belt is held on the running line, so when the belt is wrapped around the outer periphery of the first pulley, the belt is twisted appropriately and the inner circumferential surface 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 on the second pulley, and the belt can be prevented from coming off the second pulley. 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 from the plane of the paper on which the layout in Fig. 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 from the plane of the paper on which the layout in Fig. 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 portion of the belt when restricting the twist of the belt.

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

[0013] The above method prevents the belt between the first pulley and the fourth pulley from twisting, 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 causing the belt to ride 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 it is necessary to rotate the first pulley in a direction that loosens the mounting bolt, engaging the rotary tool with the mounting bolt and rotating the first pulley in the direction that loosens the mounting bolt will cause the first pulley to come off the layout. Therefore, after engaging the engaging portion of the rotating plate with the side of the first pulley, the rotary tool is engaged with the engaging portion and rotated in the direction of loosening the mounting bolt, so that the first pulley can be rotated in the direction of loosening the mounting bolt without coming off the layout. [Effects of the Invention]

[0016] To provide a belt mounting method that can prevent the belt from slipping off the ribs of the belt from the pulley on which it is first wound, and thus prevent the belt from coming off, when the belt stretchable in the circumferential direction is mounted between four or more pulleys. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 2 is an explanatory diagram of the layout of the accessory drive unit according to the present embodiment. [Figure 2] FIG. 2 is an explanatory diagram of a crank pulley according to the embodiment. [Figure 3] FIG. 2 is a perspective view of the mounting jig according to the embodiment. [Figure 4] 1A and 1B are six-view diagrams of a mounting jig according to the present embodiment. [Figure 5] FIG. 10 is an explanatory diagram of an auxiliary jig according to the present embodiment. [Figure 6] 4A and 4B are explanatory diagrams of a rotation plate according to the embodiment. [Figure 7] FIG. 10 is an explanatory diagram of a procedure (b) of the belt mounting method according to the present embodiment. [Figure 8] FIG. 10 is an explanatory diagram of step (c) of the belt mounting method according to the present embodiment. [Figure 9]FIG. 10 is an explanatory diagram of step (d) of the belt mounting method according to the present embodiment. [Figure 10] 10A and 10B are explanatory diagrams of steps (e) and (f) of the belt mounting method according to the present embodiment. [Figure 11] FIG. 10 is an explanatory diagram of step (f) of the belt installation method according to the present embodiment. [Figure 12] FIG. 10 is an explanatory diagram of step (f) of the belt installation method according to the present embodiment. [Figure 13] FIG. 10 is an explanatory diagram of the attachment position of the auxiliary jig according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[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] Specifically, in the accessory drive unit 10 shown in FIG. 1, when a V-ribbed belt 5 that can be stretched in the circumferential direction is wound between a crank pulley 1 connected to the drive shaft of the engine power, an air conditioner compressor pulley 2 connected to the rotating shaft of the air conditioner compressor, an alternator pulley 3 connected to the rotating shaft of the alternator, and a water pump pulley 4 connected to the rotating shaft of the water pump, the V-ribbed belt 5 wound between the air conditioner compressor pulley 2, the alternator pulley 3, and the water pump pulley 4 is described as being wound around the crank pulley 1. In this embodiment, the center distances of the crank pulley 1, the air conditioner compressor pulley 2, the alternator pulley 3, and the water pump pulley 4 are fixed and cannot be changed. Also, 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 circumferential surface of the V-ribbed belt 5. A boss 12 is formed in the center of the crank pulley 1, into which a crankshaft of an engine or the like is inserted. The crank pulley 1 is rotatably attached to the accessory drive unit 10 by fastening a mounting bolt to the boss 12.

[0021] Further, 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 similar to the elongated hole 13. As a result, engaging portions 91 and 92 of the rotary plate 9, which will be described later, are engaged with the elongated holes 13 and 14 on the side surface of the crank pulley 1. A detailed description will be given later.

[0022] Furthermore, 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, which will be described later, is fitted.

[0023] (Air conditioner compressor pulley 2) The air conditioner compressor pulley 2 has a pulley groove 21 formed on its outer periphery that can mate with a rib 51 formed on the inner circumferential surface of the V-ribbed belt 5. A shaft that moves in conjunction with the air conditioner compressor is inserted into a boss 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 22.

[0024] (Alternator pulley 3) The alternator pulley 3 has a pulley groove 31 formed on its outer periphery that can mate with a rib 51 formed on the inner circumferential surface 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 comes into contact. That is, the outer peripheral surface of the V-ribbed belt 5 comes into contact with the outer periphery of the water pump pulley 4 in a state where the outer peripheral surface of the V-ribbed belt 5 is bent so that it faces inward, i.e., in a reverse bent state. The water pump pulley 4 has no pulley groove or flange formed on its outer periphery, and the outer periphery of the water pump pulley 4 has a flat shape. A shaft that is linked 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. By using a back pulley, the winding angle of the V-ribbed belt 5 wound around the pulley adjacent to the back pulley can be increased, thereby improving power transmission efficiency. In other words, slippage 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 in the core wire, and is less susceptible to sudden decreases in tension compared to a so-called high modulus belt, which is a belt with a high elastic modulus. The V-ribbed belt 5 has ribs 51 formed on its inner peripheral surface that can be fitted into the pulley grooves 11 of the crank pulley 1, etc. The V-ribbed belt 5 has a flat outer peripheral surface.

[0027] Furthermore, arrow V in FIG. 1 indicates the running direction of V-ribbed belt 5, and the rotation direction of crank pulley 1 when V-ribbed belt 5 runs in this running direction is defined as leftward direction A, and the rotation direction opposite to 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 that is 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 has a shape that protrudes from the winding portion 72 onto the outer periphery of the crank pulley 1 so that 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.

[0030] The winding portion 72 has an arc shape so as to fit along the flange portion 15 on the side 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 of the crank pulley 1. Further, on the outer side of the hook portion 72, a recessed portion 74 corresponding to the protruding portion 73 is formed.

[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 and closable closing member.

[0034] The circumferential portion 82 may have a circular, elliptical, pear-shaped, rectangular or triangular shape 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 portion of the inner periphery of the circumferential portion 82 that comes into contact with the V-ribbed belt 5 has a curved shape. In this way, since the inner circumference of the peripheral portion 82 of the auxiliary jig 8 has a curved shape, when the V-ribbed belt 5 is wound around the accessory drive unit 10, the auxiliary jig 8 prevents excessive force from being applied to parts of the V-ribbed belt 5 when regulating the twisting of the V-ribbed belt 5.

[0035] As shown in Figure 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 completed.

[0036] (Rotating Plate 9) As shown in FIG. 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 front 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 engagement portion 91 (92) has a support portion 911 (921) that is press-fit into holes 95 (96) formed at both ends of the plate 94, and a locking portion 912 (922) that is provided at the tip of the support portion 911 (921) and has an outer diameter larger than the support portion 911 (921). The engaging portions 91 and 92 of the rotary plate 9 are engaged with the elongated holes 13 and 14 on the side surface of the crank pulley 1 .

[0038] (How to attach the belt) Next, a belt installation 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 in advance 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.

[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 floating 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 forward. The back surface of the V-ribbed belt 5 is the outer peripheral surface of the V-ribbed belt 5. Here, the auxiliary jig 8 is arranged such that the space 83 on the inner periphery 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. Therefore, 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 a moderately twisted state with the outer periphery facing towards the front.

[0041] <Step (c)> Next, as shown in FIG. 8, the mounting jig 7 is attached 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 surface of the crank pulley 1. In this case, the pressing portion 71 is disposed so as 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. The winding portion 72 also covers the edge of the flange portion 15 on the side surface of the crank pulley 1, the edge being the portion around which the V-ribbed belt 5 is wound when it is temporarily wound.

[0042] <Step (d)> 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] <Step (e)> 10 , the locking portions 912 and 922 of the engaging portions 91 and 92 of the rotating plate 9 are inserted into the central portions of the elongated holes 13 and 14 formed in the side surface of the crank pulley 1, the central portions having approximately the same outer diameter as the locking portions 912 and 922, and the rotating plate 9 is turned leftward in direction A so that the locking portions 912 and 922 of the engaging portions 91 and 92 are locked onto both ends of the elongated holes 13 and 14, which have smaller outer diameters than the locking portions 912 and 922, and the engaging portions 91 and 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] Normally, the crank pulley 1 is attached to the accessory drive unit 10 by fastening a mounting bolt that can be fitted 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 the 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 the rotating plate 9 is attached to the side of the crank pulley 1, a torque wrench 99 is fitted to the hexagonal nut 93, and the torque wrench 99 or the like is rotated in the direction of loosening the mounting bolt, so that the crank pulley 1 can be rotated in the direction of loosening the mounting bolt 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 is fitted to 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 a leftward direction A, which is a direction from the water pump pulley 4, which is a rear pulley, toward the air conditioner compressor pulley 2. If the crank pulley 1 were to be rotated clockwise, i.e., in 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 be twisted, causing the V-ribbed belt 5 to slip on the water pump pulley 4, which is the back pulley, and causing the ribs of the V-ribbed belt 5 to shift on the alternator pulley 3, which may cause the V-ribbed belt 5 to ride up on the alternator pulley 3. Therefore, by rotating the crank pulley 1 in the left direction A, the above problem can be prevented.

[0047] The crank pulley 1 is rotated leftward in direction A from the state shown in Fig. 10 to the state shown in Fig. 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 Fig. 11 to the state shown in Fig. 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 retaining 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] In addition, in the above-described installation method, as shown in FIG. 13, the position of 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 position of the space 83 on the inner peripheral side of the circumferential portion 82 of the auxiliary jig 8 were to be located outside the outer peripheral 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 peripheral 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 would ride up due to rib misalignment toward the front side of the air conditioner compressor pulley 2, and the V-ribbed belt 5 may 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 the V-ribbed belt 5 is wound 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 the ribs shifting 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, auxiliary jig 8 positions space 83 on the inner circumferential side of circumferential portion 82 on running line L of V-ribbed belt 5 between crank pulley 1 and air conditioner compressor pulley 2. When V-ribbed belt 5 is passed through space 83 on the inner circumferential side of circumferential portion 82 of auxiliary jig 8, V-ribbed belt 5 is held on running line L between crank pulley 1 and air conditioner compressor pulley 2. Therefore, when V-ribbed belt 5 is wound around the outer periphery of crank pulley 1, V-ribbed belt 5 is twisted appropriately so that the inner circumferential surface of V-ribbed belt 5 faces the side surface of crank pulley 1. As a result, when crank pulley 1 is rotated, rib displacement of V-ribbed belt 5 does not occur at air conditioner compressor pulley 2, and V-ribbed belt 5 can be prevented from coming off 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 steps, the V-ribbed belt 5 can be wound around the accessory drive unit 10 consisting of the crank pulley 1, the air conditioner compressor pulley 2, the alternator pulley 3, and the water pump pulley 4.

[0053] (Other embodiments) In the above embodiment, a belt installation method has been described in which the V-ribbed belt 5 is wound around the accessory drive unit 10 having four pulleys: a crank pulley 1, an air conditioner compressor pulley 2, an alternator pulley 3, and a 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] The above describes an embodiment of the present invention, but the present invention is not limited to the above embodiment, and can be implemented in various modifications within the scope of the claims. [Explanation of symbols]

[0057] 1 Crank pulley (first pulley) 2 Air conditioner compressor pulley (second pulley) 3 Alternator pulley (third pulley) 4 Water pump pulley (4th pulley) 5 V-ribbed belt 7 Mounting jig 71 Presser foot 72 Winding section 8 Auxiliary Jig 81 Opening 82 Peripheral part 83 Space 9 Rotating Plate 91·92 Engagement part 93 Hexagon nut (fitting part) 10. Auxiliary drive unit L running line

Claims

1. A belt mounting method in which a belt that is stretchable in a circumferential direction is wound around at least four pulleys that are laid out in this order: a first pulley, a second pulley, a third pulley, and a fourth pulley, an auxiliary jig having an opening and a circumferential portion, the space on the inner circumferential side of the circumferential portion being disposed on a running line of the belt between the first pulley and the second pulley; and a step of passing the belt from the opening into the space on the inner circumferential side of the circumferential portion. a step of attaching an attachment jig to the first pulley, the attachment jig including a pressing portion disposed to face an outer periphery of the first pulley and a winding portion that is pressed against the first pulley by the tension of the belt; a step of guiding 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 in a state where an inner circumferential surface of the belt faces a side surface 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 an inner periphery of the circumferential portion of the auxiliary jig has a curved portion that comes into contact with the belt.

3. the fourth pulley is a back pulley with which the outer circumferential surface of the belt comes into contact, 2. The belt mounting method according to claim 1, wherein in the step of rotating the first pulley, the first pulley is rotated in a direction from the fourth pulley toward the second pulley.

4. In the step of rotating the first pulley, 4. The belt mounting method according to claim 1, wherein, when 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 method comprises: 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 engaging portion on a side surface of the first pulley, 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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