JPH0564561U - Overtension prevention structure for power transmission belt of engine accessory - Google Patents

Abstract

(57) [Summary] [Purpose] The adjust bar is changed when the belt is hung on several pulleys driven in series with other auxiliaries and the belt length is changed and the maximum tension position is displaced. Adjustable without doing. In a belt tension adjusting mechanism for transmitting power from a pulley attached to a crankshaft of a vehicle engine to an engine accessory via a belt, adjustment for moving along an adjust bar 7 for moving and adjusting a drive pulley of the accessory. The movement limiting member 20 is interposed between the element 13 and the support piece 9 formed at the end portion of the adjusting bar 7 so that the movement limiting member 20 and the end portion of the adjusting bar 7 are located at the belt tension limit position. Interfering with each other makes it possible to regulate over tension.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure for preventing overtension at a belt position when power is transmitted from an engine crankshaft to an engine accessory.

[0002]

[Prior Art]

 Conventionally, there are belt tension adjusting mechanisms shown in, for example, FIGS. 4 and 5, and the belt tension adjusting mechanism is an engine accessory installed on the side surface of the engine 1, for example, a drive pulley 3 and a crank pulley 4 of an alternator 2. It adjusts the tension of the drive belt 5 that is attached between the adjuster 7 and the drive belt 5. The adjuster bar 7 is attached to the upper side of the mounting bracket 6 of the alternator 2, and the adjuster bar 7 is attached to the mounting bracket 6 of the alternator 2. A long hole 8 having a predetermined length from the starting point T1 having a substantially circular arc shape centering on the mounting fulcrum C1 to the maximum tension point T2 is provided so that the free end side has a substantially right angle as shown in FIG. A support piece 9 having an insertion hole 10 for the adjustment bolt 12 is formed by being bent. The adjusting bar 7 formed in this manner has one end thereof attached to a predetermined position of the engine 2 by a mounting bolt 11.

The adjusting bolt 12 is inserted into the insertion hole 10 of the supporting piece 9 of the adjusting bar 7 thus mounted, and the adjusting element 13 is screwed into the adjusting bolt 12. The adjusting element 13 is formed in a block shape and has a threaded portion 14 threadedly engaged with the adjust bolt 12, and a bolt hole 15 through which a positioning bolt 16 is inserted in a direction orthogonal to the threaded portion 14. It is installed all over.

The adjusting bolt 12 is screwed into the threaded portion 14 of the adjusting element 13 thus formed, and the positioning bolt 16 is inserted into the bolt hole 15, and the positioning bolt 16 is further adjusted by the adjusting bar 7. When the adjusting bolt 12 is rotated in the screw advancing direction by being inserted into the elongated hole 8 of the alternator 2 and screwed into the screw portion 2c screwed to the upper mounting piece 2b of the alternator 2, the adjusting element 13 is moved through the positioning bolt 16 through the positioning bolt 16. The adjuster bar 7 is moved to the support piece 9 side along the elongated hole 8, and the alternator 2 is moved integrally with the adjuster bar 7 around the mounting fulcrum C1 to adjust the tension of the drive belt 5 and position it at the optimum position. By tightening the bolt 16, the alternator 2 is set in position.

[0005]

[Problems to be solved by the device]

 However, in this conventional belt tension adjusting mechanism, the arrangement position of the alternator 2 changes in the front-rear direction of the engine depending on whether or not another engine accessory is attached, and the drive pulley 17 of another accessory is also changed. It is generally driven by the same drive belt 18 in series, and therefore, the length of the drive belt 18 is changed with respect to the drive belt 5, and thus the length of the long hole 8 of the adjusting bar 7 is changed. At the position T3 before the maximum tension position T2, the maximum tension position, that is, the belt tension limit is reached. Therefore, if the positioning bolt 16 is inadvertently set to the maximum tension position T2 side during adjustment, belt over tension will result and the pulley will be in use. There have been problems such as breakage of the supporting portion and disconnection of the drive belt 18.

The present invention has been made to solve the above-mentioned conventional problems. It is hung on several pulleys driven in series with other auxiliaries and the belt length is changed to maximize the tension. It is an object of the present invention to provide an overtension preventing structure that can adjust an adjust bar without changing the position when the position is displaced.

[0007]

[Means for Solving the Problems]

 In order to solve the above technical problems, the present invention adjusts the drive pulley of an auxiliary machine in a belt tension adjusting mechanism that transmits power from a pulley mounted on a crankshaft of a vehicle engine to an engine auxiliary machine via a belt. A movement limiting member is interposed between the adjusting element that moves along the adjusting bar and the support piece formed at the end of the adjusting bar, and the movement limiting member and the adjusting bar end are positioned at the belt tension limit position. This is due to the overtension prevention structure in the power transmission belt of the engine accessory, which is configured to interfere with each other and to control over tension.

[0008]

[Action]

 With the above configuration, it functions to prevent the adjustment element from moving from the belt tension limit position to the over tension side.

[0009]

【Example】

 Next, an embodiment of the present invention will be described with reference to FIGS. 1, 2 and 4. This belt tension adjusting mechanism is the same as the conventional one, and it is an engine accessory, for example, a drive pulley 3 and a crank pulley of an alternator 2. 4 and the drive pulleys 17 of other accessories, the tension of the drive belt 18 is adjusted. The adjust bar 7 is attached to the upper side of the mounting bracket 6 of the alternator 2. Numeral 7 is a free end side in which a long hole 8 having a predetermined length from a substantially arcuate starting point T1 centered on a mounting fulcrum C1 of the alternator 2 to the mounting bracket 6 to a maximum tension point T2 is provided. A support piece 9 having an insertion hole 10 for the adjusting bolt 12 is formed at the end portion and is bent at a substantially right angle. The adjusting bar 7 thus formed is attached at one end thereof to the engine 2 at a predetermined position with a mounting bolt 11.

The adjusting bolt 12 is inserted into the insertion hole 10 of the support piece 9 of the adjusting bar 7 thus mounted, and the adjusting element 13 is screwed into the adjusting bolt 12. The adjusting element 13 is formed in a block shape and has a threaded portion 14 threadedly engaged with the adjust bolt 12, and a bolt hole 15 through which a positioning bolt 16 is inserted in a direction orthogonal to the threaded portion 14. It is installed all over.

A movement limiting plate (also referred to as a movement limiting member) 20 is attached to the adjusting element 13 thus provided. The movement restricting plate 20 has a mounting piece 21 and a stopper piece 22 formed in a substantially L shape, and the stopper piece 22 has a notch portion 23 which is opened at an end thereof and through which the adjusting bolt 12 can be inserted. Further, a mounting hole 24 is formed at a position of a predetermined distance L from the end face of the stopper piece 22 so as to be aligned with the bolt hole 15 penetrating the adjusting element 13. In the movement restricting plate 20 thus formed, the notch 23 is fitted into the adjusting bolt 12, the mounting hole 24 is aligned with the bolt hole 15 of the adjusting element 13, and the positioning bolt 16 is inserted. Further, the positioning bolt 16 is inserted into the elongated hole 8 of the adjusting bar 7 and screwed into the screw portion 2c screwed on the upper mounting piece 2b of the alternator 2, and when the adjusting bolt 12 is rotated in the screwing direction, the adjusting element is adjusted. 13 is moved along the elongated hole 8 toward the support piece 9 side of the adjusting bar 7 via the positioning bolt 16, and when the stopper piece 22 of the movement limiting plate 20 comes into contact with the support piece 9 of the adjusting bar 7, the adjusting piece 13 is adjusted. The center of the bolt 12 is configured to be aligned with the maximum tension position, that is, the belt tension limit T3 at a position T3 before the maximum tension position T2.

Therefore, even if the drive belt 18 is hooked on the drive pulleys of a plurality of engine auxiliaries by attaching the movement limiting plate 20 and the belt length is changed, the maximum tension position T2 is not reached. It is possible to prevent erroneous adjustment in advance, and by using this movement limiting plate 20, the adjusting bar 7 can be unified without changing, and the number of parts can be minimized. The number of steps can be reduced.

Next, FIG. 3 shows a modified example of the movement restricting member. In FIG. 3, a stopper collar 25 is used in place of the movement restricting plate 20 and the stopper bolt 25 is inserted into the adjusting bolt 12. It is formed in a cylindrical shape so that its length is formed to have a predetermined size M from the end surface of the support piece 9 of the adjusting bar 7, and when the adjusting bolt 12 is rotated to bring the adjusting element 13 into contact with the stopper collar 25, positioning is performed. The center of the bolt 16 is configured to match the maximum tension position, that is, the belt tension limit T3 at a position T3 before the maximum tension position T2. Therefore, the same effect as that of the above-described embodiment is obtained.

[0014]

EFFECTS OF THE INVENTION Since the present invention is configured as described above, by attaching the movement limiting member, the drive belts are hooked on the drive pulleys of a plurality of engine accessories, and the belt lengths thereof are reduced. Even if it is changed, erroneous adjustment to the maximum tension position can be prevented beforehand, and by using this movement limiting plate, the adjust bar can be unified without changing the adjust bar. The number of parts can be minimized and the management man-hours can be reduced.

[Brief description of drawings]

FIG. 1 is a partial plan view of a maximum tension side of an adjust bar and is an explanatory view of belt tension.

FIG. 2 is an exploded perspective view of the portion of FIG.

FIG. 3 is a plan view showing another mode of the movement limiting member.

FIG. 4 is a front view showing a belt adjustment mechanism that drives an engine accessory to be connected to an engine via a belt.

5 is a view on arrow A in FIG. 4. FIG.

[Explanation of symbols]

 1 Engine 2 Alternator (Engine Auxiliary Machine) 3,17 Drive Pulley 4 Crank Pulley 7 Adjust Bar 9 Support Piece 13 Adjusting Element 18 Drive Belt 20 Movement Limiting Plate (Movement Limiting Member) 25 Stopper Collar (Movement Limiting Member)

Claims (1)

[Scope of utility model registration request] 1. A belt tension adjusting mechanism for transmitting power from a pulley attached to a crankshaft of a vehicle engine to an engine accessory via a belt, wherein the drive pulley of the accessory is moved along an adjust bar for adjusting movement. A movement limiting member is interposed between the adjusting element and the support piece formed at the end of the adjusting bar, and the movement limiting member and the end of the adjusting bar interfere with each other at the belt tension limit position. Excessive tension prevention structure in the power transmission belt of the engine accessory that is configured to be able to regulate over tension.