JP2012154455A - Structure of auto-tensioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of an auto-tensioner with which a belt can be arranged under an energizing force smaller than the prescribed energizing force and the belt can be adjusted to be in a prescribed tension state without confirming a slack amount of the belt.SOLUTION: An auto-tensioner comprises a body part, an arm part which is urged with a force corresponding to an angle with the body part and a pulley which is pivotally supported by the top end of the arm part, wherein the body part includes a fixing means which fixes the body to the engine side and an engagement member which rotates integrally with the body, a stopper part capable of contacting with the engagement member is disposed on the arm part, when the body part and the arm part form a prescribed relative angle in the temporarily fastening state of a fastening bolt, the stopper part comes into contact with the engagement member, thereby, turning movement to at least one direction of the engagement member is suppressed and, in the main fastening state of the fastening bolt, the contacting between the stopper part and the engagement member is released and the swinging movement of the arm part is permitted.

Description

  The present invention relates to a structure of an auto tensioner that maintains a constant tension of a belt that transmits a driving force to an auxiliary machine of an engine.

  Automobile engines come with accessories such as alternators, water pumps, air conditioner compressors, etc. The rotational force of the crankshaft is transmitted to these accessories via pulleys and belts, and each is driven to rotate. Is done. However, since the temperature change around the engine is severe and the temperature change due to the use environment of the automobile is also added, the belt tension always changes. Therefore, an auto tensioner has been conventionally used to keep the tension constant.

  FIG. 10 shows the auto tensioner 104 and the belt 102 in a conventional use state. In the auto tensioner 104 shown in FIG. 10, an arm portion 108 is pivotally attached to a main body portion 106 fixed to an engine (not shown) by a fastening bolt 110. A pulley 109 is rotatably attached to the tip of the arm portion 108. Although not shown in the figure, the arm portion 108 is biased from the main body portion 106, and the pulley 109 is pressed against the side surface of the belt 102 to give a pressing force. As a result, the arm portion 108 swings in accordance with the change in the tension of the belt 102, and the belt 102 can always be held in a state in which a constant tension is applied without slack.

  FIG. 11 shows the state of the auto tensioner 104 when the length of the belt 102 varies. The solid line portion in FIG. 11 indicates the state of the belt 102 and the auto tensioner 104 with respect to the minimum value of the belt length variation, and the two-dot chain line portion indicates the state of the belt 102 and the auto tensioner 104 with respect to the maximum value. Show. As apparent from FIG. 11, when the length of the belt 102 varies, the angle of the arm portion 108 also varies accordingly, so that the pressing force deviates from an appropriate value, and the tension generated in the belt 102 deviates from the appropriate value. . As described above, when the belt 102 is used in a state where the tension is out of the proper value, the allowable range may be exceeded due to a change in the belt length due to a temperature change or aged deterioration. In this case, there may be a case where the performance of the auto tensioner 104 cannot be sufficiently exhibited.

  Such belt variations can be eliminated by the configuration disclosed in Patent Document 1. In Patent Document 1, it is possible to finely adjust the arrangement angle of the main body of the auto tensioner with an adjusting screw after the auto tensioner is installed. Thus, even if the belt length varies, this variation can be eliminated by adjusting the arrangement angle of the main body.

  By the way, it is difficult to visually confirm the difference in belt tension unless a slack can be clearly confirmed. For this reason, in the auto tensioner configured as in Patent Document 1, fine adjustment is possible, but the belt tension state requires manual confirmation of the belt runout. Relying on the senses of the person.

  Therefore, a configuration for obtaining an appropriate tension without excess or deficiency is conceivable. For example, according to the configuration disclosed in Patent Document 2, the length of the spring that biases the arm is kept constant when adjusting the distance between the belt and the pulley in order to eliminate variations in the belt length. A stopper is adopted. As a result, the pulley and the arm can be moved while the urging force applied to the arm is kept constant, so that the tension can always be set to an appropriate tension.

  Next, returning to FIG. 10, the operation at the time of installation or replacement of the belt will be described. When the belt 102 is installed or replaced, it is necessary to largely retract the arm portion 108 against urging. In FIG. 10, the retracted state of the arm portion 108 is indicated by a two-dot chain line portion. In the case of a configuration such as the auto tensioner 104 shown in FIG. 10, the swing width of the arm portion 108 in use is adjusted to be around 10 degrees, but the belt is installed or replaced to be retracted to an angle exceeding this swing width. In this case, a very large force must be applied to the arm portion 108.

  A configuration for facilitating this is disclosed in Patent Document 3. In the auto tensioner described in Patent Document 3, a spring with a damper is employed as a mechanism for applying an urging force to the arm, but a tool for pushing back the arm against the force of the spring can be connected. A bulging portion is provided. As a result, a large force can be applied, the arm can be pushed back easily, and the belt can be easily replaced.

Japanese Utility Model Publication No. 63-145047 Japanese Patent Laid-Open No. 7-19303 JP 2007-239767 A

  However, with the configuration described in Patent Document 2, the problem of adjusting the appropriate tension described in Patent Document 1 can be solved, but it is necessary to attach and detach a stopper for keeping the length of the spring constant each time the tension is adjusted. Therefore, it cannot be said that the working efficiency is good, and there is a possibility that the removal of the stopper is forgotten.

  Further, in the configuration described in Patent Document 3, a relatively large urging force is applied to the arm of the auto tensioner in order to obtain a pressing force necessary for tensioning the belt with an appropriate tension. A very large force is required to retreat larger than the swing width. Then, the work for installing or replacing the belt is performed while maintaining the retracted state, and the workability is not good. Further, since retracting the arm larger than the swing width may exceed the allowable stress of the spring material, this configuration also has a problem that options for the spring material and the spring shape are limited.

  Therefore, in order to solve the above problem, the present invention can arrange the belt under a biasing force smaller than the biasing force to the arm necessary for the pressing force for tensioning the belt with an appropriate tension, and An object is to provide an auto tensioner structure that can be adjusted to an appropriate tension state without checking the amount of slack in the belt.

In order to achieve the above object, in the invention according to claim 1, the structure of the auto tensioner is attached to the engine side with a fastening bolt, and in a temporarily tightened state, a main body portion rotatable with the fastening bolt as a turning shaft; ,
An arm portion that receives a biasing force from the main body portion with a force according to a relative angle with the main body portion;
The structure of the auto tensioner is composed of a pulley that is pivotally supported at the tip of the arm portion and presses the accessory drive belt,
The main body is
A fixing means including a bracket having a long hole and capable of rotating around the axis of the fastening bolt; and a fixing bolt for fixing the main body to the engine side;
The main body is connected to the main body, and when the main body is rotated, the main body rotates together with the main body, and the surface including the rotation trajectory of the main body according to the fastening operation of the fastening bolt. An engagement member that is vertically driven;
The arm portion is provided with a stopper portion having a contact end capable of contacting the rotated engaging member,
In the temporarily tightened state of the fastening bolt, when the main body portion and the arm portion have a predetermined relative angle, the contact end of the stopper portion comes into contact with the engagement member, so that the locking member and the Deter rotation of the main body in at least one direction,
In the final tightening state of the fastening bolt, the engagement member is driven in the substantially vertical direction, the contact between the stopper portion and the engagement member is released, and the arm portion provided with the stopper portion is swung. It is possible to operate.

  If comprised in this way, the relative angle between the main-body part and an arm part can be adjusted in the temporary fastening state which can be rotated centering on the axis | shaft of a fastening bolt. And the main-body part is fixed by fastening the bracket of the main-body part in which the long hole was formed after this relative angle adjustment to the engine side with a fixing bolt.

  In addition, the engagement member that is driven in a direction substantially perpendicular to the surface including the rotation trajectory of the main body portion according to the fastening state of the fastening bolt is a stopper portion on the arm portion according to the rotation of the main body portion in the temporarily tightened state. Approaches the abutting end. When the main body is rotated, the relative angle with the arm is changed. At this time, the arm portion receives an urging force corresponding to the relative angle with the main body portion, and as a result, the pulley pivotally supported by the arm portion applies a pressing force to the accessory driving belt. When the relative angle between the main body portion and the arm portion becomes a predetermined value, the pressing force that the pulley applies to the accessory driving belt becomes a predetermined value. That is, a predetermined tension is applied to the accessory drive belt. And the contact end of the stopper part provided in the position which suppresses rotation of the engagement member to at least one direction contacts the contact member, and the rotation operation of the engagement member and the main body part is suppressed.

  Further, in the final tightened state of the fastening bolt, the engaging member is driven in a substantially vertical direction with respect to the surface including the rotation track of the main body portion, and is separated from the stopper portion. The contact state is released. Accordingly, the arm portion can swing around the fastening bolt while receiving an urging force corresponding to a relative angle with the main body portion with respect to the main body portion fixed to the engine side.

  Due to the above-described action, the main body can be temporarily fastened to the engine with a fastening bolt at a relative angle at which a large biasing force is not applied from the main body to the arm. Then, the pulley is applied to the accessory drive belt, the main body is rotated about the axis of the fastening bolt, and the relative angle between the main body and the arm becomes a predetermined angle. The position where the predetermined pressing force is applied can be determined and fixed by the fixing means. That is, the installation work of the belt and the auto tensioner are facilitated.

  Further, the stopper member comes into contact with the engaging member that comes close to the contact end of the stopper portion in the temporarily tightened state when the urging force acting between the main body portion and the arm portion becomes a predetermined value. Since the rotation operation in the direction is suppressed, the biasing force can be easily adjusted. That is, it is not necessary to repeatedly check the degree of bending of the accessory drive belt, and an optimum biasing state can be set by one operation of rotating the main body, thereby improving work efficiency. Here, the “rotating operation in at least one direction” means that the relative angle between the main body part and the arm part is increased or decreased in at least one direction.

  Furthermore, after setting and fixing the main body portion in a relative angle state where a predetermined urging force (a predetermined pressing force is applied to the accessory drive belt) is applied, the fastening bolt is finally tightened to follow it. The engaging member is separated from the stopper portion, the contact is released, and the arm portion can be shifted to a state in which the arm portion can freely swing with respect to the main body portion. That is, it is not necessary to store a state in which a predetermined urging force is obtained by using another member (stopper portion) having a stopper function. Accordingly, it is possible to save the trouble of removing the stopper member after the setting, so that the work efficiency can be improved. Further, it is possible to prevent the auto tensioner from being in a state of not functioning due to forgetting to remove it.

Further, the structure of the auto tensioner according to the invention of claim 2 is added to the structure of claim 1 above.
The engaging member is
In the temporarily tightened state, it is urged so as to be pressed against the upper surface of the stopper portion in a direction substantially perpendicular to the surface including the rotation trajectory of the main body portion,
When the bolt side end of the engagement member is pushed down by fastening of the fastening bolt, the abutting side end that is the opposite end follows the direction away from the stopper in the substantially vertical direction,
When the main body part and the arm part have a predetermined relative angle, the stopper member comes into contact with the engaging member by dropping the engaging member immediately before the contact end of the stopper part,
The stopper portion prevents the engaging member and the main body from rotating in a direction in which a relative angle between the main body and the arm is reduced.

  With this configuration, in the temporarily tightened state of the fastening bolt, the bolt side end portion of the engagement member is not pushed down by the fastening bolt, and therefore, the contact side is urged toward the stopper portion acting on the engagement member. The end portion is pressed against the upper surface of the stopper portion formed on the arm portion. What is pressed is in a direction substantially perpendicular to the surface including the rotation trajectory of the main body. At this time, if the main body is rotated while the pulley is pressed against the accessory drive belt, the abutting side end of the abutting member slides on the stopper upper surface. In addition, the stopper portion is formed in advance up to a position where the relative angle relationship between the main body portion and the arm portion becomes a predetermined urging force. That is, when the urging force from the main body portion to the arm portion becomes a predetermined urging force in the temporarily tightened state, the engaging member that has slid on the stopper portion with the rotation of the main body portion is the arm portion. It will be in the state which falls to an upper surface, and the contact end of a stopper part will be in a contact state with an engagement member.

  By such an action, the biasing force is strengthened while confirming the movement of the engaging member that is slidably contacted on the stopper portion with the rotation of the main body portion in the temporarily tightened state, and the engaging member falls onto the arm portion from the end portion of the stopper portion. It is possible to confirm that a predetermined urging force (that is, a predetermined pressing force against the accessory driving belt) is working depending on the state. This is set so that if the main body is rotated so that the main body and the arm are at a predetermined angle, a predetermined urging force is applied to the arm and a predetermined pressing force is applied to the accessory drive belt. It can be done.

  Also, when the main body part is rotated together with the engagement member to a relative angle at which a predetermined urging force works, the stopper part comes into contact with the direction in which the rotation of the engagement member in the direction in which the urging force is weakened, Even if the support of the main body is weakened, a predetermined urging force can be maintained. Therefore, the predetermined urging force can be set quickly and accurately without checking the state of the accessory drive belt.

Furthermore, the structure of the auto tensioner of the invention according to claim 3 is added to the structure of claim 2,
The bracket further includes a position adjustment bolt in which a shaft is arranged in a tangential direction with respect to the rotation of the main body portion around the fastening bolt,
A plurality of engaged portions are formed on the outer periphery of the position adjusting bolt,
An engaging claw that engages with the engaged member is formed at the abutting side end of the engaging member,
The engagement claw is engaged with the engaged portion when the main body portion and the arm portion have a predetermined relative angle.

  If comprised in this way, the engagement member which slid on the stopper part with rotation of a main-body part will remove | deviate a stopper part and will fall to the arm part side, when it becomes predetermined | prescribed biasing force. Then, the engaging claw at the abutting side end of the engaging member is engaged with the engaged portion of the position adjusting bolt, and the rotation of the position adjusting bolt is suppressed.

  By such an action, when the urging force from the main body portion to the arm portion becomes a predetermined urging force, the angle does not become smaller than the angle at which the main body portion and the arm portion become an appropriate urging force, and the engaging member Since the rotation of the position adjusting bolt is suppressed by the engagement between the engaging claw and the engaged portion of the position adjusting bolt, it is possible to prevent the urging force from being applied to the arm portion more than necessary. . That is, it is possible to set a state in which a predetermined urging force is applied without visually confirming the state of the accessory drive belt and the relative position between the main body portion and the arm portion, thereby improving workability. Can do.

Further, the structure of the auto tensioner of the invention according to claim 4 is added to the structure of claim 1,
The engaging member is
In the temporarily tightened state, it is urged so as to be pressed against the upper surface of the arm portion in a direction substantially perpendicular to the surface including the rotation trajectory of the main body portion,
When the bolt side end of the engagement member is pushed down by fastening of the fastening bolt, the abutting side end that is the opposite end follows the direction away from the stopper in the substantially vertical direction,
When the main body portion and the arm portion are at a predetermined relative angle, the engaging member abuts against the abutting end of the stopper portion,
The stopper portion prevents the engagement member from rotating in a direction in which an angle between the main body portion and the arm portion increases.

  With such a configuration, in the temporarily tightened state of the fastening bolt, the bolt side end portion of the engaging member is not pushed down by the fastening bolt, so that the engaging member is armed by urging in the arm portion direction acting on the fastening member. Pressed against the upper surface of the part. What is pressed is in a substantially vertical direction in a plane including the rotation trajectory of the main body. In this temporarily tightened state where the biasing force is smaller than a predetermined value, when the main body is rotated in the direction in which the biasing force is increased, the contact side of the engaging member that rotates integrally with the main body The end portion rotates while sliding in a position close to the arm portion. By this turning operation, the relative angle between the main body and the arm is widened, and the biasing force to the arm is increased. When the main body portion and the arm portion have a predetermined relative angle and a predetermined urging force is applied to the arm portion, the contact end of the stopper portion contacts the contact member, and rotation of the main body portion is suppressed. The rotation of the main body is adjusted by operating the position adjustment bolt.

  By such an action, the urging force from the main body to the arm can be adjusted by the position adjusting bolt, so even if the operator interrupts the fastening operation, the urging force at that time is stably maintained. . In addition, when the main body is rotated in the direction in which the urging force is increased and the predetermined urging force is obtained, the stopper portion abuts against the abutting member, and the rotation of the main body portion is suppressed. It is possible to prevent a force from being applied to the arm portion.

  As described above, according to the structure of the auto tensioner of the present invention, in order to stretch the accessory driving belt with an appropriate tension, only a biasing force smaller than a predetermined biasing force applied from the main body portion to the arm portion is required. The accessory drive belt can be placed without working. Therefore, the work becomes easy and the work efficiency can be improved.

  Further, since the stopper portion on the arm portion and the engaging member connected to the main body portion are in contact with each other at a relative angle between the main body portion and the arm portion when a predetermined urging force is applied, the visual determination is made. It is not necessary to confirm the state of tension of the difficult belt by the slack of the belt or the like, and it is possible to set it to a predetermined state accurately and quickly.

1 is an overall perspective view of an auto tensioner according to a first embodiment of the present invention. It is explanatory drawing of the installation procedure of the autotensioner of FIG. 1, (a) is a state when urging | biasing force is smaller than predetermined value, (b) is urging | biasing force being predetermined value and a temporary fastening state, (c) is It is the figure which showed urging | biasing force with a predetermined value and a final fastening state. It is sectional drawing corresponding to the installation procedure of the auto tensioner of FIG. 2, (a) is the sectional view on the AA line of FIG. 2 (a), (b) is the sectional view on the BB line of FIG. FIG. 2C is a cross-sectional view taken along the line CC of FIG. It is a whole perspective view of the auto tensioner in the 2nd Embodiment of this invention. FIG. 5 is an explanatory diagram of an installation procedure of the auto tensioner of FIG. 4, (a) shows a state when the urging force is smaller than a predetermined value, and (b) shows a state when the urging force becomes a predetermined value. FIG. 6 is a cross-sectional view corresponding to the installation procedure of the auto tensioner in FIG. 5, (a) is a cross-sectional view taken along the line DD in FIG. 5 (a), and (b) is a temporary cross-sectional view taken along the line EE in FIG. The figure which showed the fastening state and (c) is the figure which showed the final fastening state in the EE sectional view of FIG.5 (b). It is a whole perspective view of the auto tensioner in the 3rd Embodiment of this invention. FIGS. 8A and 8B are explanatory diagrams of the installation procedure of the auto tensioner of FIG. 7, in which FIG. 7A shows a state when the urging force is smaller than a predetermined value, and FIG. 8B shows a state where the urging force becomes a predetermined value. It is sectional drawing corresponding to the installation procedure of the auto tensioner of FIG. 8, (a) is FF sectional view taken on the line of FIG. 8 (a), (b) is provisional in the GG sectional view of FIG.8 (b). The figure which showed the fastening state and (c) is the figure which showed the final fastening state in the GG cross section of FIG.8 (b). It is a whole perspective view of the conventional auto tensioner. It is the figure which showed the state with respect to belt length dispersion | variation of the auto tensioner of FIG.

  Embodiments of the present invention will be described below with reference to the drawings. Note that the auto tensioner of the present invention includes a main body portion, an arm portion, and a pulley pivotally supported by the arm portion. The outline of the present invention is as follows.

  The tension to be applied to the belt is determined by the assumed use situation and material of the belt. In order to apply the tension, it is possible to determine in advance how much pressing force the pulley of the arm portion should press the belt. On the other hand, the urging force between the main body part and the arm part depends on the physical size (length and mass) of the main body part and the arm part and the strength of the urging means provided between them. As a function of the relative angle of the part. Therefore, in order to obtain the tension to be applied to the belt, it is possible to determine how much the urging force between the main body portion and the arm portion should be obtained, which is the relative angle between the main body portion and the arm portion. Can be managed with.

  However, the stronger the pulley is pressed against the belt, the more the belt will bend and the arm will swing. In addition, since the actual belt varies in length within the range of individual dimensional errors, the degree of deflection is also different. For this reason, the magnitude of the swing of the arm portion is different in each case. That is, both the main body part and the arm part are rotated, and the degree of rotation differs in each case, so it is not easy to grasp the relative angle of each other. The autotensioner according to the present invention makes it easy to know that the relative angle between the main body portion and the arm portion has reached a predetermined value.

(First embodiment)
The structure of the auto tensioner according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 shows a part of an auto tensioner 4 in use and an accessory driving belt (hereinafter also simply referred to as “belt”) 2 whose tension is adjusted by the auto tensioner 4.

  In the auto tensioner 4 in the present embodiment, the center of the main body portion 6 is attached to the engine main body by a fastening bolt 10. The main body 6 has an arc-shaped long hole 16 a centering on the axis of the fastening bolt 10 and a bracket 6 b in which a tool connecting portion 17 is formed. In addition, although the long hole of a bracket is demonstrated as circular arc shape throughout this specification, if a bracket can rotate centering on the axis | shaft of a fastening bolt, it will not be limited to circular arc shape.

  The rotation position of the main body 6 around the fastening bolt 10 is fixed at a predetermined position by the long hole 16a and the fixing bolt 16b (fixing means 16). Then, in the vicinity of the fastening bolt 10, the arm portion 8 is connected so that the one end 8 a overlaps the main body portion 6. The arm 8 is connected so that the one end 8a can swing even when the fastening bolt 10 is finally tightened around the axis of the fastening bolt 10. A pulley 9 that presses the belt 2 is pivotally supported on the other end 8b of the arm portion 8 in a freely rotatable state. Although not shown here, the arm portion 8 is urged from the main body portion 6 by a force corresponding to a relative angle with the main body portion 6 by an urging means such as an elastic member such as a spring. If a relative angle is given to the main body portion 6 and the arm portion 8 while the pulley 9 is pressed against the belt 2, a pressing force corresponding to the angle is given to the belt 2. The belt 2 obtains a predetermined tension by the pressing force from the pulley 9.

  With the above-described configuration, the main body 6 can rotate around the axis of the fastening bolt 10 by placing the fastening bolt 10 in a temporarily tightened state and loosening the fixing bolt 16b. In this rotatable state, the arm portion 8 connected to the main body portion 6 can also freely rotate, so that the attachment work can be made easy when the belt 2 is attached. . When the attachment of the belt 2 is completed and the pulley 9 is pressed against the belt 2 to rotate the main body 6 in the direction in which the urging force acts on the arm portion 8, a large force against the urging force is required. In that case, the main body 6 can be rotated by assembling the tool 19 to the tool connecting portion 17 provided in the main body 6.

  Here, the structure near the fastening bolt 10 will be described. The fastening bolt 10 is inserted into a sleeve 6a that protrudes upward from the bottom of the main body 6 through the arm portion 8, and is fastened to the engine. An engaging member 12 fixed to the sleeve 6a in a seesaw manner with the intermediate position as a fulcrum 12a extends outward from the fastening bolt 10 side. A spring 12b is provided below the bolt side end 12e of the engaging member 12, and the bolt side end 12e is urged so as to be pushed upward. Thereby, the outer side end part (contact side end part 12d) of the engaging member 12 is urged in a direction approaching the arm part 8 side. In other words, the engagement member 12 swings in a direction substantially perpendicular to the surface including the rotation track of the main body 6.

  On the other hand, an arc-shaped protrusion is provided as a stopper portion 14 on the arm portion 8. FIG. 1 shows a state where the adjustment is completed from the main body 6 to the arm 8 and a predetermined urging force is applied. That is, the main body 6 and the arm 8 are fixed in a state where the belt 2 is pressed and has a predetermined relative angle determined in advance in the design stage. In this state, one end (contact end 14 t) of the stopper portion 14 is in contact with the contact-side end portion 12 d that is the outer end portion of the engagement member 12. Further, in this figure, the fastening bolt 10 is in a temporarily tightened state, but when in the final tightened state, the head of the fastening bolt 10 pushes down the bolt side end 12e of the engaging member 12, so that the contact side end 12d. Lifts from the arm 8. Next, the installation procedure of the auto tensioner 4 will be described with reference to FIGS.

  FIG. 2A shows a state in which the fastening bolt 10 is temporarily tightened and the main body 6 is positioned in a region where the urging force is small. Moreover, (b) has shown the state when the main-body part 6 is rotated to the state used as the predetermined urging | biasing force using the tool 19. FIG. And (c) fixes the bracket 6b of the main-body part 6 with the fixing bolt 16b in order to fix the position of the main-body part 6 in the state which became predetermined | prescribed urging | biasing force, and makes the fastening bolt 10 into a final fastening state. The state which removed the tool 19 is shown. Note that the fact that a predetermined urging force is obtained between the arm portion 8 and the main body portion 6 while the pulley 9 is pressed against the belt 2 means that a predetermined tension is applied to the belt 2. This means that a pressing force is applied to the belt 2 and the belt 2 has obtained a predetermined tension.

  3A is a cross-sectional view taken along line AA in FIG. 2A, FIG. 3B is a cross-sectional view taken along line BB in FIG. 2B, and FIG. 3C is FIG. It is a CC sectional view taken on the line of FIG.

  In the state of FIG. 2A, the engagement member 12 overlaps above the stopper portion 14. At this time, since the fastening bolt 10 is in a temporarily tightened state, as shown in FIG. 3A, the bolt-side end portion 12e of the engaging member 12 is lifted by the spring 12b, and the engaging member 12 is pressed. The contact-side end portion 12d is pressed against the stopper portion 14.

  In the state of FIG. 2B in which the main body 6 is rotated from this state and a predetermined urging force is applied to the arm 8, the contact-side end 12 d of the engaging member 12 that rotates integrally with the main body 6 is It has reached the area where the stopper portion 14 is not formed, and comes into contact with the upper surface of the arm portion 8 as shown in FIG. 3B due to the urging force of the spring 12b. In other words, the contact-side end portion 12 d falls from the upper surface of the stopper portion 14 to the upper surface of the arm portion 8. Then, simultaneously with the fall, the contact end 14t in the circumferential direction of the stopper portion 14 contacts the contact-side end portion 12d (see FIG. 2B).

  As described above, the stopper portion 14 is formed in a region having a smaller angle than that in which a predetermined urging force is generated between the main body portion 6 and the arm portion 8 and in which the trajectory of the engaging member 12 is projected. . This is represented as a hatched projection area 15 in FIG. As described above, since the contact end 14t of the stopper portion 14 is in contact with the contact end portion 12d of the engagement member 12 in the state of FIG. 2B, the arm portion 8 and the main body portion 6 are biased. The angle cannot be changed in the direction of weakening. That is, it functions as a lock mechanism for preventing the angle between the main body 6 and the arm 8 from being reduced due to the reaction of the urging force. Accordingly, the reaction force of the pressing force applied to the belt 2 is received by the tool 19 connected to the main body 6.

  In FIG. 2 (c), the main body 6 (bracket 6b) is fastened to the engine side with the fixing bolt 16b in the locked state, and fixed so that the pulley 9 together with the main body 6 and the arm 8 does not move. The tool 19 is removed. And installation is completed by making fastening bolt 10 into a final tightening state. As shown in FIG. 3C, in the final tightening state, the bolt-side end portion 12e of the engagement member 12 is pushed down by the head of the fastening bolt 10, so that the contact-side end portion 12d is lifted. Note that the lifting movement of the engagement member 12 is a direction substantially perpendicular to the surface including the turning locus of the main body 6 and is driven by the fastening operation of the fastening bolt 10.

  In order to show the positional relationship between the contact-side end portion 12d and the stopper portion 14 in the lifted state, the position of the stopper portion 14 is indicated by a virtual line in FIG. As described above, in the final tightened state, the engaging member 12 is lifted to a position higher than the stopper portion 14, so that the locking to the engaging member 12 by the stopper portion 14 is released, and the arm portion 8 is located between the main body portion 6 and the arm portion 8. It becomes a swingable state while receiving an urging force according to the relative angle. This is because the belt 2 expands and contracts under various conditions while it is used, so that the arm portion 8 needs to be able to move both in the direction in which the urging force increases and in the direction in which it decreases.

  Thus, according to the structure of the auto tensioner 4 in the present embodiment, it is possible to set the tension to be a predetermined tension without checking the tension of the belt 2. That is, the pressing force to be applied to the belt 2 can be obtained from the tension required by the belt 2. And, from the strength of the urging means installed in the main body part 6, the arm part 8 and the main body part 6, the urging force necessary for the arm part 8 determines the angle between the main body part 6 and the arm part 8. It can be obtained at the design stage. Accordingly, the position of the stopper portion 14 is provided or the relative angle of the engaging member 12 with respect to the main body portion 6 is determined in advance so that the above-described locking mechanism works at the relative angle between the main body portion 6 and the arm portion 8. Thus, without checking the tension of the belt 2, the relative angle between the main body portion 6 and the arm portion 8 can be set to a predetermined relative angle, and a predetermined pressing force can be applied to the belt 2.

  Moreover, even if the belt length varies and the rotation position of the main body 6 changes accordingly, the operator can confirm that the relative angle between the main body 6 and the arm 8 has reached a predetermined value. Since it can be recognized, a predetermined pressing force can always be applied to the belt 2.

  Further, when the fastening bolt 10 is brought into the final tightening state, the engaging member 12 is separated from the stopper portion 14. Therefore, it is necessary to prepare a stopper member or the like separately in order to adjust to a predetermined appropriate pressing force. Absent. As a result, work efficiency can be improved, and forgetting to remove the stopper member can be prevented.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS.

  FIG. 4 shows the auto tensioner 34 in use and a part of the belt 2 whose tension is adjusted by the auto tensioner 34. The auto tensioner 34 in the present embodiment is fastened by a fastening bolt 40 at the center of the main body 36 similarly to the auto tensioner 4 of FIG. 1 in the first embodiment. Further, the arcuate elongated hole 46a formed around the axis of the fastening bolt 40 formed in the bracket 36b and the fixing bolt 46b (fixing means 46), the rotational position of the main body 36 around the fastening bolt 40 is predetermined. The same applies to the configuration fixed at the position. The pulley 39, the sleeve 36a, the fulcrum 42a, the one end 38a and the other end 38b of the arm portion 38, the bolt side end portion 42e, and the like are the same as those in the first embodiment.

  However, the bracket 36 b is provided with a position adjusting bolt 48 as a mechanism for rotating the main body 36, and the abutting side end 42 d of the engaging member 42 is extended to the vicinity of the position adjusting bolt 48. This is different from the first embodiment. Below, it demonstrates centering on this different point.

  The position adjusting bolt 48 is arranged with its axial direction substantially tangential to the rotation of the main body 36. And the front-end | tip of the position adjustment volt | bolt 48 is screwed by the internal thread formed in the fixed piece 49 provided in the engine main body. Accordingly, when the position adjusting bolt 48 is rotated, the rotation position of the main body 36 can be changed. Further, in the auto tensioner 4 of FIG. 1, unlike the case where the tool 19 is attached to the tool connecting portion 17 and the main body portion 6 is rotated, even if the operation is interrupted, the position adjusting bolt 48 and the fixing piece 49 are screwed together. Thus, the rotation position at the time of the interruption is stored.

  The stopper portion 44 formed on the arm portion 38 of the present embodiment is formed in the same shape as the stopper portion 14 formed on the arm portion 8 of FIG. However, the engagement member 42 connected to the main body portion 36 in FIG. 4 has a tip of the abutting side end portion 42d extending toward the position adjusting bolt 48 side. An engagement claw 42f is formed on the extended contact end 42d toward the bracket 36b. Further, an engaged portion 48b is formed in a region on the axis of the position adjusting bolt 48 where the engaging claw 42f faces. Thereby, the engaging claw 42f can be engaged with the engaged portion 48b when moving downward.

  Hereinafter, the installation procedure of the auto tensioner 34 in the present embodiment will be described with reference to FIGS. 5 and 6.

  FIG. 5A shows a state in which the fastening bolt 40 is temporarily tightened and the relative angle between the main body 36 and the arm 38 is positioned in a region where the urging force is reduced. FIG. 5B shows a state where the main body 36 is rotated to a state where a predetermined urging force is obtained by rotating the position adjusting bolt 48. After the position of the main body portion 36 is determined, the case where the main body portion 36 is fixed to the engine side with the fixing bolt 46b and the fastening bolt 40 is in the final tightening state is the same as FIG. Omitted and described with reference to FIG.

  6A is a cross-sectional view taken along the line DD in FIG. 5A, and FIG. 6B is a cross-sectional view taken along the line EE in FIG. 40 shows a temporarily tightened state, and FIG. 6C is a cross-sectional view taken along line EE of FIG. 5B, and shows a final tightened state of the fastening bolt 40.

  In the state of FIG. 5A, the engaging member 42 overlaps the stopper portion 44. At this time, since the fastening bolt 40 is in a temporarily tightened state, as shown in FIG. 6A, the bolt side end portion 42e of the engaging member 42 is urged in the direction to be lifted by the spring 42b. The combined member 42 is pressed against the upper surface of the stopper portion 44.

  In the state of FIG. 5B in which the main body portion 36 is rotated from this state and a predetermined urging force is applied, the engaging member 42 that rotates integrally with the main body portion 36 is located in a region where the stopper portion 44 is not formed. As shown in FIG. 6 (b), the arm 42 is brought into contact with the upper surface by the biasing force of the spring 42b. That is, the engaging member 42 falls from the upper surface of the stopper portion 44 to the upper surface of the arm portion 38. At the same time, the contact end 44t of the stopper portion 44 is also in contact. As described above, the stopper portion 44 is formed in a region where a locus of the engaging member 42 is projected in an angle region smaller than the relative angle between the main body portion 36 and the arm portion 38 that exhibits a predetermined urging force. This is represented as a hatched projection area 45 in FIG. 5B.

  Here, the engaging member 42 in the present embodiment has an engaging claw 42f formed on the abutting side end portion 42d, and the abutting end 44t of the stopper portion 44 is formed as shown in FIG. In the state of contacting the engaging member 42, the engaging claw 42f is engaged with the engaged portion 48b of the position adjusting bolt 48 (FIG. 6B). As a result, the position adjusting bolt 48 is locked, and the main body 36 can be prevented from rotating to a region where the position adjusting bolt 48 is greater than or equal to a predetermined urging force. As described above, in the state of FIG. 6B, as shown in FIG. 5B, the stopper portion 44 moves the main body portion 36 in the direction in which the urging force between the main body portion 36 and the arm portion 38 is reduced. Prevent rotation. At the same time, the engagement between the engaged portion 48b of the position adjusting bolt 48 and the engaging claw 42f of the locking member 42 prevents the main body 36 from rotating in the direction in which the urging force increases. Therefore, the relative angle between the main body 36 and the arm 38 is satisfactorily maintained in a state where a predetermined urging force is obtained.

  In FIG. 6C, the fixing bolt 46b is fastened in a state where the lock is applied. And installation is completed by making fastening bolt 40 into a final tightening state. As shown in FIG. 6C, in the final tightening state, the bolt side end portion 42e of the engaging member 42 is pushed down by the head of the fastening bolt 40, so that the contact side end portion 42d is lifted. In order to explain the positional relationship between the contact-side end portion 42d and the stopper portion 44 in the lifted state, the position of the stopper portion 44 is indicated by a virtual line in FIG. Thus, in the final tightening state, the engaging member 42 is lifted to a position higher than the stopper portion 44, and the engaged portion 48b of the position adjusting bolt 48 and the engaging claw 42f are in a separated state, so that the arm portion 38 is in a separated state. Becomes swingable with respect to the main body 36. The lifting movement of the engaging member 42 is driven by the fastening operation of the fastening bolt 40 in a direction substantially perpendicular to the surface including the rotation locus of the main body 36.

  As described above, according to the structure of the auto tensioner 34 in the present embodiment, as in the case of the auto tensioner 4 shown in FIG. 1 in the first embodiment, the predetermined tension can be applied without checking the tension of the belt 2. It is possible to set the tension to be a predetermined tension. In addition, in the present embodiment, it is possible to prevent the main body portion 36 from rotating to a position where an urging force is applied more than necessary, and it is possible to install the urging force in a state where the predetermined urging force is obtained more accurately and quickly. Is possible.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS.

  FIG. 7 shows the auto tensioner 54 in use and a part of the belt 2 whose tension is adjusted by the auto tensioner 54. Unlike the auto tensioners 4 and 34 shown in FIGS. 1 and 4 shown in the first and second embodiments, the auto tensioner 54 in the present embodiment has a stopper portion 64 in the swing direction of the arm portion 58. The contact side end 62d of the engagement member 62 is in contact with the contact end 64s on the opposite side. Hereinafter, this configuration will be described mainly with respect to differences from the first embodiment. The pulley 59, the sleeve 56a, the fulcrum 62a, the one end 58a and the other end 58b of the arm portion 58, the bolt side end portion 62e, and the like are the same as those in the first and second embodiments.

  In the configuration of the auto tensioner 54 in the present embodiment, a mechanism for rotating the main body portion 56 is provided in the bracket 56b of the main body portion 56 in the same manner as the auto tensioner 34 shown in FIG. 4 in the second embodiment. Although the position adjusting bolt 68 is employed, in the present embodiment, the engaged portion is not formed on the position adjusting bolt 68. Further, the engaging member 62 has the same structure as the engaging portion 12 of the auto tensioner 4 of FIG. 1 in the first embodiment.

  However, the stopper portion 64 contacts the engaging member 62 on the opposite side of the engaging member 62, that is, in the rotational direction in which the pulley 59 pivotally supported by the arm portion 58 increases the pressing force against the belt 2. It is formed at a position where the contact end 64s contacts. The stopper portion 64 and the engaging member 62 are in contact with each other when a predetermined biasing force is applied. Therefore, in a state where the urging force according to the relative angle between the main body portion 56 and the arm portion 58 is smaller than the predetermined urging force, the engaging member 62 is brought into the sliding contact state on the arm portion 58 by the urging force of the spring 62b. It has become.

  Hereinafter, the installation procedure of the auto tensioner 54 in the present embodiment will be described with reference to FIGS. 8 and 9.

  FIG. 8A shows a state in which the fastening bolt 60 is temporarily tightened and the relative angle between the main body portion 56 and the arm portion 58 is positioned in a region where the urging force is reduced. FIG. 8B shows a state when the main body 56 is rotated to a state where a predetermined urging force is obtained by rotating the position adjusting bolt 68. In addition, after the position of the main body portion 56 is determined, the case where the main body portion 56 is fixed to the engine side with the fixing bolt 66b and the fastening bolt 60 is in the final tightening state is the same as FIG. Omitted and described with reference to FIG.

  9A is a cross-sectional view taken along the line FF in FIG. 8A, and FIG. 9B is a cross-sectional view taken along the line GG in FIG. The tightened state is shown. FIG. 9C is a cross-sectional view taken along the line GG of FIG. 8B and shows a final tightened state of the fastening bolt 60.

  In the state of FIG. 8A, the engaging member 62 is in sliding contact with the arm portion 58 at a position away from the stopper portion 64. It can be seen from FIG. 9A that the bolt side end 62e of the engaging member 62 is lifted by the spring 62b, and the contact side end 62d of the engaging member 62 is in sliding contact with the arm portion 58.

  In this state, when the position adjusting bolt 68 is rotated and the rotation of the main body portion 56 advances and a predetermined urging force is applied, the contact of the engaging member 62 rotating integrally with the main body portion 56 is achieved. The contact end 62d is in contact with the contact end 64s of the stopper 64 facing the rotation direction. Again, in the contact state between the contact end 64s of the stopper 64 and the contact end 62d shown in FIG. 9B, the contact of the engagement member 62 is the same as in FIG. 9A. The contact-side end portion 62d is in sliding contact with the arm portion 58.

  As described above, in the present embodiment, when the main body 56 is rotated in the direction in which the urging force of the arm portion 58 increases, the contact end 64s of the stopper portion 64 is located at a position where the predetermined urging force is obtained. Abutting on the engaging member 62, further rotation is suppressed. And since the main-body part 56 is rotated with the position adjustment volt | bolt 68 screwed together to the fixed piece 69, even if rotation work is interrupted, the position is hold | maintained favorably.

  Subsequently, in this manner, in a state in which the urging from the main body portion 56 to the arm portion 58 becomes a predetermined urging force, the rotation position of the main body portion 56 is fixed by the fixing bolt 66b, and the fastening bolt 60 is fastened. This is the final tightening state. The state when the final tightening state is reached is shown in FIG. As can be seen from this figure, the bolt side end 62 e of the engaging member 62 is pushed down by the head of the fastening bolt 60. On the other hand, the abutting side end 62 d is lifted to a position higher than the height of the stopper portion 64. Thereby, since the stopper part 64 and the engaging member 62 can maintain a separation state, the arm part 58 will be in the state which can rock | fluctuate freely. The lifting movement of the engaging member 62 is driven by the fastening operation of the fastening bolt 60 in a direction substantially perpendicular to the surface including the rotation locus of the main body 56.

  As described above, in the auto tensioner 54 shown in the present embodiment, the configuration shown in the second embodiment is provided by providing the stopper portion 64 on the side that prevents the rotation in the direction in which the urging force increases. Since it is possible to know that a predetermined pressing force is applied to the belt 2 without checking the tension of the belt 2 with a simpler configuration, it is possible to prevent a state in which the bias is applied more than necessary. It becomes possible.

  In the first embodiment described above, the tool connecting portion is provided as a mechanism for rotating the main body, and the main body is rotated by a tool assembled thereto, but the present invention is not limited thereto. Instead, it may be configured to be rotated by the position adjusting bolt as shown in the second and third embodiments. Conversely, instead of the position adjustment bolts shown in the second and third embodiments, the main body is rotated by the combination of the tool connecting portion and the tool shown in the first embodiment. May be.

  Further, in each of the above-described embodiments, the configuration in which the contact is made only from one side with respect to the circumferential direction of the rotation track of the engagement member is shown as an example, but the configuration in which the stopper portion is provided to contact from both sides It does not matter. If comprised in this way, since the rotation of an engaging member is suppressed with respect to both the direction where pressing force increases and the direction which decreases, for example, the tool connection part shown in 1st Embodiment, and Even with the configuration of a combination of tools, it is possible to stably and satisfactorily maintain a state in which a predetermined urging force is applied, and it is possible to improve work efficiency.

  The auto tensioner of the present invention can be widely used not only for automatic adjustment of the tension of an accessory driving belt of an automobile but also for belt driving as a transmission means for transmitting rotational motion.

2 Belt (auxiliary drive belt)
4, 34, 54 Auto tensioner 6, 36, 56 Main body 6b, 36b, 56b Bracket 6a, 36a, 56a Sleeve 8, 38, 58 Arm 8a, 38a, 58a One end 8b, 38b, 58b The other end 10, 40, 60 fastening bolts 10a, 40a, 60a fastening bolt shafts 12, 42, 62 engaging members 12a, 42a, 62a fulcrums 12d, 42d, 62d abutting side ends 12e, 42e, 62e bolt side ends 42f engaging claws 14 44, 64 Stopper portions 14t, 44t, 64s Abutting ends 16, 46, 66 Fixing means 16a, 46a, 66a Long holes 16b, 46b, 66b Fixing bolt 17 Tool connecting portion 48, 68 Position adjusting bolt 48b Engaged portion 15, 45 Projection area

Claims (4)

It is attached to the engine side with a fastening bolt, and in a temporarily tightened state, a main body that can be turned around the fastening bolt as a turning shaft;
An arm portion that receives a biasing force from the main body portion with a force according to a relative angle with the main body portion;
The structure of the auto tensioner is composed of a pulley that is pivotally supported at the tip of the arm portion and presses the accessory drive belt,
The main body is
A fixing means including a bracket having a long hole and capable of rotating around the axis of the fastening bolt; and a fixing bolt for fixing the main body to the engine side;
The main body is connected to the main body, and when the main body is rotated, the main body rotates together with the main body, and the surface including the rotation trajectory of the main body according to the fastening operation of the fastening bolt. An engagement member that is vertically driven;
The arm portion is provided with a stopper portion having a contact end capable of contacting the rotated engaging member,
In the temporarily tightened state of the fastening bolt, when the main body portion and the arm portion have a predetermined relative angle, the contact end of the stopper portion comes into contact with the engagement member, so that the locking member and the Deter rotation of the main body in at least one direction,
In the final tightening state of the fastening bolt, the engagement member is driven in the substantially vertical direction, the contact between the stopper portion and the engagement member is released, and the arm portion provided with the stopper portion is swung. Auto-tensioner structure characterized in that operation is possible. The engaging member is
In the temporarily tightened state, it is urged so as to be pressed against the upper surface of the stopper portion in a direction substantially perpendicular to the surface including the rotation trajectory of the main body portion,
When the bolt side end of the engagement member is pushed down by fastening of the fastening bolt, the abutting side end that is the opposite end follows the direction away from the stopper in the substantially vertical direction,
When the main body part and the arm part have a predetermined relative angle, the stopper member comes into contact with the engaging member by dropping the engaging member immediately before the contact end of the stopper part,
The auto-tensioner according to claim 1, wherein the stopper portion prevents the engagement member and the main body from rotating in a direction in which a relative angle between the main body and the arm is reduced. Structure. The bracket further includes a position adjustment bolt in which a shaft is arranged in a tangential direction with respect to the rotation of the main body portion around the fastening bolt,
A plurality of engaged portions are formed on the outer periphery of the position adjusting bolt,
An engaging claw that engages with the engaged member is formed at the abutting side end of the engaging member,
The structure of the auto tensioner according to claim 2, wherein the engaging claw is engaged with the engaged portion when the main body portion and the arm portion have a predetermined relative angle. The engaging member is
In the temporarily tightened state, it is urged so as to be pressed against the upper surface of the arm portion in a direction substantially perpendicular to the surface including the rotation trajectory of the main body portion,
When the bolt side end of the engagement member is pushed down by fastening of the fastening bolt, the abutting side end that is the opposite end follows the direction away from the stopper in the substantially vertical direction,
When the main body portion and the arm portion are at a predetermined relative angle, the engaging member abuts against the abutting end of the stopper portion,
The structure of the auto tensioner according to claim 1, wherein the stopper portion prevents the engaging member from rotating in a direction in which an angle between the main body portion and the arm portion increases.