JPH04110253U - Belt tensioner structure - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the durability or reliability of a belt tensioner by shortening the rod stroke of the tensioner body, thereby making it applicable as a belt tensioner for V-belts. [Structure] The base end 21a of the first arm part 21 supports the tension pulley 12 on the distal end side, and the arm length is shorter than that of the first arm part 21, and the distal end side is an engaging part 22a. The tensioner body 3 includes a tension arm 2 consisting of a base end 22b of the second arm portion 22, and a tensioner main body 3, which is provided with a rod 37 that engages with the engagement portion of the tension arm and has two fixing portions 32a and 32b. ,
The connecting part of the tension arm 2 and one fixed part 32a of the tensioner main body 3 are pivotally supported by the tensioner fulcrum shaft 6 so as to be relatively rotatable, while the other fixed part 32b of the tensioner main body 3 is connected to the other fixed part 32b of the tensioner main body 3. A set position adjustment mechanism 7 is provided that allows the set position adjustment mechanism 7 to be fixed at any position.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a belt tensioner structure.

0002

[Conventional technology]

Belt tensioners originally handle tension caused by the elongation of the belt due to long-term use. This is to recover the decrease in tension and maintain a predetermined tension. Various types of tensioners have been developed, among which maintenance-free The system uses the spring force of the spring and the hydraulic damper mechanism to There is a so-called auto-tensioner that can always apply a predetermined tension to the bolt (for example, For example, see Japanese Patent Application Laid-Open No. 121344/1983).

0003 In addition, as shown in the above-mentioned known example, this auto tensioner is One end of the tension arm that supports the tension pulley in between is connected to the engine. It is pivoted on one side, while the other end is biased by a spring via a piston. The rod of the tensioner body having the rod is brought into contact with the tensioner body, and The tension arm is rotated by the spring force of the spring, and is lifted. Apply a predetermined tension to the timing belt that is wrapped around the tension pulley. It is generally configured as follows.

0004

[Problem that the idea aims to solve]

However, such an autotensioner, as disclosed in the above-mentioned known example, It is used exclusively to adjust the tension of the engine timing belt, and is When used for belt tension adjustment, the following problems may occur. Due to these concerns, it was rarely used for V-belts.

[0005] In other words, V-belts have less initial variation in belt length than timing belts. And the durability elongates greatly with use, so as shown in Figure 4, the tension adjustment is In order to do this, it is necessary to increase the amount of movement of the tension arm. (See ranges from point b to point c and point d to e in Figure 4).

[0006] On the other hand, as in the above-mentioned known example, the tension arm and the tensioner body are separately machined. If it is configured to be assembled on the engine side, there will be variations in the assembly of each of them. To absorb this, the tension arm must be extended that much further. (See the range from point a to point b and the range from point c to point d in Figure 4).

[0007] Furthermore, as in the above-mentioned known example, a tension pulley is installed at the intermediate position of the tension arm. If the configuration is such that the tension pulley is the ratio of the arm length to the arm length from the pivot point to the engagement point with the damper mechanism; In other words, since the arm ratio is greater than 1, the tension pulley required for tension adjustment is The tensioner body requires a greater amount of movement than the amount of movement corresponding to the arm ratio. will be required.

[0008] As a result, the tension arm moves the distance for hanging the belt (from point 0 to point a in Figure 4). It is a structure that can move over a very large range between point 0 and point e, including the range). required.

[0009] Note that here, the tensioner that adjusts the movement of the tension arm (i.e., belt tension) is The main body is attached to the tension pulley on the belt and the tension arm is tightened. After fixing it to the mounting base (point a position in Figure 4), start the operation and adjust the required tension. It is something to do. Therefore, the rod of the tensioner body is in the range from point a to point e in FIG. The tension arm expands and contracts within the belt, causing not only the initial variation in belt length but also the tension arm. Also, assembly variations in the tensioner body must be absorbed by the expansion and contraction of the rod. Therefore, the rod stroke of the tensioner body becomes longer. .

0010 In this way, as the amount of movement of the tension arm increases, the rod of the tensioner body As the stroke becomes longer, the spring that biases the rod of the tensioner body will , as the amount of expansion and contraction increases, the tension is actually adjusted at the final stage of expansion. Therefore, at the final stage of this long extension range, and with the required spring force. If you try to maintain it, use a spring with a larger spring constant (stronger It is necessary to use

[0011] As a result, first of all, the piston that is in the tensioner body and supports the rod is The longer the piston slides, the more likely it is that the piston will seize. Durability or reliability may be impaired.

Secondly, as the rod stroke of the tensioner body becomes longer, it is necessary to set the spring constant of the spring larger, so the protruding force of the rod changes greatly at both the front and rear ends of the stroke range ( The belt tension P ₁ and P ₅ in FIG. 4) increases the wear of the rod or the tension arm contacting the rod, thereby impairing its durability or reliability.

[0013] Third, the actual belt tension adjustment is performed using a spring that has a large amount of expansion and contraction. Since this is done at the final stage of tensioning, it is difficult to use even though a strong spring is used. Only the smallest spring force range can contribute to belt tension adjustment, and the There is room for improvement in terms of effective use of spring capacity.

[0014] Therefore, in the present invention, by shortening the rod stroke of the tensioner body, Improves the durability or reliability of belt tensioners and promotes effective use of component capacity. , a belt tensioner that can also be used for tension adjustment of V-belts. This was done to suggest a new structure.

[0015]

[Means to solve the problem]

In the present invention, as a means for solving this problem, the invention according to claim 1 is used. has a predetermined arm length and supports a tension pulley on its tip side. The base end of the first arm part, and the distal end side of the arm having a shorter arm length than the first arm part. A tension arm formed by integrally joining the proximal end of the second arm part with the engagement part and a piston with a rod that engages with the engagement part of the tension arm. It is inserted into the cylinder while being biased by the ring, and the tension is held in place. and a tensioner body forming two fixing parts to the tensioner mounting base, Connect the connecting part of the tension arm and one fixed part of the tensioner body to the tensioner. The tensioner is pivoted relative to the tensioner mounting base using the tensioner fulcrum shaft, while the tensioner Attach the tensioner body to the other fixed part of the tensioner body and attach the tensioner fulcrum shaft to the other fixed part of the tensioner body. A set position that allows it to be fixed at any position within a predetermined rotation range as the center. It is characterized by the provision of a position adjustment mechanism.

[0016] Further, in the invention according to claim 2, in the belt tensioner structure according to claim 1, Then, the engaging part and the rod of the tensioner body are connected to the engaging part of the tension arm. An auxiliary adjustment mechanism that is interposed between the tip and the tip and can adjust the distance between the two is detachable. It is characterized by the fact that it was set up in

[0017]

[Effect]

In the present invention, the following effects can be obtained by adopting such a configuration. Ru. That is, in the invention according to claim 1, the tension pulley supported by the tension pulley The joint part of the arm and one fixed part of the tensioner body are connected by the tensioner fulcrum shaft. It is pivoted so that it can rotate relative to each other, and it is set in the other fixed part of the tensioner body. Since the rod of the tensioner body is equipped with a position adjustment mechanism, the rod of the tensioner body is While it is in contact with the engagement part of the arm, rotate the tensioner body as appropriate to set it to the desired position. position (i.e., the position where the tension pulley contacts the belt with a predetermined tension) Therefore, by fixing the position at point a (corresponding to point a in Fig. 3), the tensioner body can be The above-mentioned tension arm and tension are It reliably absorbs assembly variations in the Shona main body and positions and secures both in the appropriate relative position. can be determined. Therefore, Fig. 3 (characteristic of the belt tensioner structure of the present invention) As shown in Fig. 4, the tensioner body assembly variations and tension To eliminate the movement range of the tension arm to accommodate variations in the assembly of the tension arm. The tensioner body can be adjusted by the amount of movement that corresponds to this assembly variation. It is possible to reduce the rod stroke (range from point a to point c) of .

[0018] In addition, in the tension arm, the first arm that supports the tension pulley is The arm length of the arm section is shorter than the arm length of the second arm section that engages with the tensioner body. Since it is set (that is, the arm length ratio is less than 1), the The rod displacement of the tensioner body is amplified and transmitted to the tension arm, Therefore, if the required movement amount of the tension arm is fixed, for example, the conventional structure Compared to the case where the arm length ratio is 1 or more as in (see the above-mentioned known example), the tension The rod stroke of the main body can be further shortened.

[0019] As a synergistic effect, the tensioner body that makes up the belt tensioner is This makes it possible to further shorten the head stroke.

[0020] In addition to the above-mentioned effect, the device according to claim 2 also has an auxiliary adjustment mechanism. To adjust the distance between the engagement part of the tensioner arm and the rod tip of the tensioner body. Therefore, the relative position between the tension arm and the tensioner body can be adjusted, and the This allows for more detailed adjustments than when adjusting the position using only the cut position adjustment mechanism. Become.

[0021]

[Effect of the idea]

Therefore, according to the inventions of the present application, the tensioner body constituting the belt tensioner is Since the rod stroke can be shortened, the sliding movement of the piston of the tensioner body The shorter the distance, the lower the probability that the piston will seize. It is possible to ensure stable operation of the belt tensioner over a long period of time, and its reliability is high. This allows for improved reliability.

[0022] It also allows the spring to be stretched to a smaller extent (in other words, to a larger extent). For example, an adjustable bell If the spring tension range is set to the same value, the strength of the spring, that is, the spring constant, should be changed. can be set smaller, and as a result, the rod or the tension in contact with it can be It is hoped that the wear of the engagement part of the extension arm will be suppressed as much as possible and its durability will be improved. However, the performance of the spring is improved to the extent that the spring can be used in a larger range of spring force. The effect is that effective utilization is promoted.

[0023] In addition, especially as in the invention as claimed in claim 2, the engagement portion of the tension arm and the tension If an auxiliary adjustment mechanism is placed between the rod tip of the main body, the auxiliary adjustment mechanism The tension arm and tensioner body are Since the relative position can be adjusted, for example, as described above, the set position adjustment mechanism Assembling the tension arm and tensioner body is easier than when it is done only by The effect is that variations can be absorbed more finely and reliably. It is something.

[0024]

【Example】

The structure of the belt tensioner of the present invention will be explained below based on the embodiment shown in the attached drawings. To clarify, FIGS. 1A and 1B show the embodiments of the invention claimed in claims 1 and 2 of the present application. A belt tensioner 1 is shown. This belt tensioner 1 is for automobiles. It adjusts the tension of the V-belt 11 for driving the engine's auxiliary equipment. It consists of a tensioner arm 2 and a tensioner body 3, and an engine body (not shown). It is integrally attached to the tensioner mounting base 4 provided in the.

Tension Arm 2 The tension arm 2 has a first arm portion 21 having a predetermined arm length and having a distal end portion 21b supporting the tension pulley 12 via the pulley shaft 5; The second arm part 22 has an arm length shorter than that of the first arm part 21 and has a distal end 22a thereof as an engaging part 22a for a tensioner main body, which will be described later, and is integrally connected by a boss part 23. There is. In this case, the first arm part 21 and the second arm part 22 extend in substantially the same direction with respect to the boss part 23, and the tension pulley 12 is positioned between each of these arm parts 21 and 22. There is.

[0026] Further, an adjustment bolt 13 is attached to the engaging portion 22a of the second arm portion 22. The tension arm 2 and tensioner body 3 are connected together as described below. In the assembled state, the head of the adjustment bolt 13 is on the side of the tensioner body 3. It comes into contact with the tip of the rod 37. Therefore, this adjustment bolt Tension arm 2 and tensioner can be connected by adjusting the amount of screwing in It is possible to adjust the relative position of the body 3 in the direction of rotation, and this implementation In the example, this adjustment bolt 13 corresponds to the auxiliary adjustment mechanism according to claim 2. Ru. In addition, this adjustment bolt 13 should be replaced if it becomes worn due to long-term use. This can be updated by replacing the In other words, the adjustment bolt 13 is used as a wear prevention member for the engaging portion 22a. Function.

Tensioner main body 3 The above-mentioned tensioner main body 3 has the same basic structure as a conventionally known one, but in order to explain the operation of the belt tensioner 1 below, its basic structure and operation will be explained with reference to FIG. 2. To briefly explain, the tensioner main body 3 is composed of a cylinder mechanism having a cylinder 33 of a predetermined diameter and a piston 34 slidably fitted into the cylinder 33. The inside of the cylinder 33 is divided by the piston 34 into a first liquid chamber 35 and a second liquid chamber 36 located on both sides in the axial direction, and a spring 42 is compressed in the second liquid chamber 36. As a result, the piston 34 is always pressed toward the first liquid chamber 35. The maximum movement position of the piston 34 in its protruding direction is regulated by a stopper ring 41 provided in the first liquid chamber 35 of the cylinder 33.

[0028] Further, the first liquid chamber 35 and the second liquid chamber 36 are provided in the piston 34 and They can communicate with each other via a liquid passage 43 that is opened and closed by a check valve 39. At the same time, sliding between the inner circumferential surface of the cylinder 33 and the outer circumferential surface of the piston 34 They can communicate with each other in a constricted state through a gap. Note that the first liquid chamber 35 is , is also in communication with the reservoir chamber 40, and in addition to the first liquid chamber 35 and the second liquid chamber 36, A hydraulic fluid is also sealed within this reservoir chamber 40.

[0029] Furthermore, a rod 3 of a predetermined length is provided at the end of the piston 34 on the first liquid chamber 35 side. 7 is coaxially attached so that it can protrude outward from one end surface 33a of the cylinder 33. I'm being kicked. Note that this rod 37 should be placed in the upper position when setting the belt tensioner 1. A setting pin 48 detachably arranged near the end surface 33a of the cylinder 33 The cylinder 33 is integrated with the piston 34 against the spring force of the spring 42. The tensioner body 3 is held in position while being immersed in the body (hereinafter, the tensioner body 3 at this time is state is called the initial state).

[0030] In the tensioner main body 3 configured in this way, this is attached to the rod 37 as described above. A load is applied in the direction of pushing the cylinder 33 into the cylinder 33 against the spring force of the spring 42. In this case, the check valve 39 is closed, so that the inside of the second liquid chamber 36 is The hydraulic fluid gradually moves to the first liquid chamber 35 side through the sliding gap, and then moves to the rod 37. moves backward slowly (damper action). On the other hand, from the load applied to the rod 37 When the spring force of the spring 42 increases, the rod 37 is aligned with the piston 34. It is physically moved in the protruding direction. In this case, the check valve 39 is opened. Therefore, the working fluid in the first fluid chamber 35 passes through the fluid passage 43 and quickly flows to the second fluid chamber 36 side. , and the rod 37 moves rapidly.

[0031] Furthermore, on one side of the tensioner main body 3, a A bracket 32 consisting of a plate of a predetermined size that serves as a fixing part is integrally formed. has been done. One end side 32a of this bracket 32 has a bolt hole 10 (see FIG. B), but the other end 32b has a predetermined length with the bolt hole 10 as the center of curvature. A long hole 9 with a diameter of 1.5 mm is formed respectively.

Assembling the tension arm 2 and the tensioner main body 3 The tension arm 2 and tensioner main body 3, respectively configured as described above, are set on the tensioner mounting base 4 side as follows, and constitute one belt tensioner 1. do. That is, first, the tensioner main body 3 is set to the initial state. Then, the tensioner main body 3 and the tension arm 2 are arranged so that the bolt hole 10 of the tensioner main body 3 and the boss portion 23 of the tension arm 2 are coaxially overlapped, and the tensioner fulcrum shaft 6 is inserted therein. This is screwed onto the tensioner mounting base 4 side, and both are pivotally supported relative to the tensioner mounting base 4 about the tensioner fulcrum shaft 6.

[0033] Next, insert the set bolt 8 into the elongated hole 9 of the bracket 32 and set the tension. the main body 3 within the length range of the elongated hole 9 (between the position shown by the solid line and the position shown by the chain line in Fig. 1A). The tensioner can be rotated in an arc around the tensioner fulcrum shaft 6 within the range.

[0034] Next, move the tensioner body 3 in the direction of arrow A around the tensioner fulcrum shaft 6. Rotate. In this case, during the rotation of the tensioner body 3, the tensioner body 3 An end surface 33a of the cylinder 33 of the body 3 is provided at the engaging portion 22a of the tension arm 2. The head of the adjustment bolt 13 is engaged with the head of the adjustment bolt 13, and both rotate integrally in the direction of the arrow. The tension pulley 12 supported by the tension arm 2 is connected to the V-belt 11. When it comes into contact with the bolt and creates a predetermined tension, it stops rotating and the set bolt The tensioner main body 3 is securely fixed to the tensioner mounting base 4 by the bolt 8. Furthermore, this In this case, if the belt tension of the V-belt 11 is somewhat excessive or insufficient, the above Adjust the screwing amount of the adjustment bolt 13 to obtain the appropriate belt tension. do. This completes the setting of the belt tensioner 1 to the tensioner mounting base 4 ( That is, the state is at point a in FIG. 3).

[0035] When the belt tensioner 1 is set, the tensioner body 3 is rotated. By adjusting the amount of movement, the belt tensioner 1 (i.e., Assembling variations between the tension arm 2 and tensioner body 3) have been definitely eliminated. It has become a state. Therefore, as in the conventional case, the tension arm 2 and the tensioner main body are It is necessary to absorb the assembly variation of the tensioner body 3 by the rod stroke of the tensioner body 3. This is not necessary at all, and the rod stroke of the tensioner body 3 can be shortened accordingly. It becomes. Specifically, it corresponds to the tension arm movement amount shown from point a to point e' in Figure 3. It would be good to have only a stroke to do this, but this stroke actually In the embodiment, the first arm portion 21 and the second arm portion of the tension arm 2 are connected as described above. The arm ratio of the arm portion 22 is set to 1 or less to reduce the rod displacement of the tensioner body 3. This is amplified and transmitted to the tension pulley 12 on the side of the tension arm 2. Therefore, the stroke amount corresponding to the above tension arm movement amount is even smaller. Become.

[0036] Next, the setting pin 48 of the tensioner main body 3 is removed. Then the rod Since the restriction on the protruding movement of 37 is lifted, the spring force of the spring 42 The V-belt 1 protrudes outward and is applied to the rod 37 via the first arm portion 21. When the restoring force of the first side and the spring force of the spring 42 are balanced, the V-beam stops. Apply the required belt tension to the belt 11.

[0037] From now on, the above-mentioned rods will be adjusted in response to changes in belt tension due to the durability of the V-belt 11. By moving the belt 37 back and forth, the belt tension of the V-belt 11 is always maintained at an appropriate state. It is something that

[0038] In this way, when the belt tensioner structure of the present invention is applied, the tension The rod stroke of the main body 3 can be made even shorter than that of the conventional structure. , the sliding distance of the piston 34 of the tensioner body 3 is also shortened, and the piston is moved by that amount. The probability of seizure occurring in the tensioner 34 is reduced, and the belt tensioner 1 is It is possible to ensure stable operation over a long period of time, and improve its reliability. It is.

Furthermore, since the spring 42 can be used in a range where the amount of extension thereof is smaller, in other words, in a range where a larger spring force can be obtained (range of belt tension P ₂ to _{P 4} in FIG. 3), For example, when the adjustable belt tension range is set to be the same, the strength of the spring 42, that is, the spring constant, can be set smaller, and as a result, the adjustment of the rod 37 or the tension arm 2 that comes into contact with it can be made smaller. Wear of the bolt 13 is suppressed as much as possible, improving its durability, and since the spring 42 can be used within a larger spring force range, effective use of its performance is promoted.

[Brief explanation of drawings]

FIG. 1A is a side view of an engine belt tensioner equipped with a belt tensioner structure according to an embodiment of the present invention.

FIG. 1B is a view taken along the line II in FIG. 1A.

FIG. 2 is an explanatory diagram of the internal structure of the tensioner main body shown in FIG. 1A.

FIG. 3 is a belt tension characteristic diagram when the belt tensioner structure of the present invention is adopted.

FIG. 4 is a belt tension characteristic diagram when a conventional belt tensioner structure is adopted.

[Explanation of symbols]

1 is a belt tensioner, 2 is a tension arm, 3 is a tensioner body, 4 is a tensioner mounting base, 5 is a pulley shaft, 6 is a tensioner fulcrum shaft, 7 is a set position adjustment mechanism,
8 is a set bolt, 9 is a long hole, 10 is a bolt hole, 11 is a V-belt, 12 is a tension pulley, 13 is an adjustment bolt, 21 is a first arm part, 22 is a second arm part,
23 is a boss portion, 32 is a bracket, 33 is a cylinder, 3
4 is a piston, 35 and 36 are liquid chambers, 37 is a rod, 3
8 is a ball seat, 39 is a check valve, 40 is a reservoir chamber, 41 is a stopper ring, 42 is a spring, 43 is a liquid passage, and 48 is a setting pin.

Claims (2)

[Scope of utility model registration request] Claim 1: A base end of a first arm having a predetermined arm length and having a tension pulley supported on its distal end; and a first arm having a shorter arm length than the first arm and having its distal end engaged. A tension arm formed by integrally connecting the proximal end of the second arm portion which is the joint portion, and a piston having a rod that engages with the engaging portion of the tension arm are biased by a spring. a tensioner body that is fitted into a cylinder and has two fixing parts relative to the tensioner mounting base formed at appropriate positions thereof, and a connecting part of the tension arm and one fixed part of the tensioner main body are attached to the tensioner mounting base. The tensioner body is pivotably supported by the tensioner fulcrum shaft so as to be relatively rotatable, while the tensioner body is fixed to the other fixed part of the tensioner body at any position within a predetermined rotation range about the tensioner fulcrum shaft. A belt tensioner structure characterized by being provided with a set position adjustment mechanism that makes it possible to adjust the set position. 2. In claim 1, an auxiliary adjustment mechanism is provided in the engaging portion of the tension arm, interposed between the engaging portion and the rod tip of the tensioner body, and capable of increasing or decreasing the distance between the two. A belt tensioner structure characterized by being detachably installed.