CN-116075656-B - Belt transmission device

Abstract

A belt transmission device is provided with a crankshaft pulley, an auxiliary pulley, a belt wound around a plurality of pulleys, and a belt tensioner capable of swinging around a swinging shaft extending parallel to the rotation axis of the auxiliary pulley, wherein a pair of tensioning pulleys are arranged in the circulating direction of the belt with the auxiliary pulley as a boundary, and tension is applied to the belt. The pair of tension pulleys is set such that the weight of any one tension pulley is heavier than the weight of any other tension pulley, so that any one of the pair of tension pulleys is hard to be sprung up by the belt.

Inventors

• KOMURA KEISUKE
• Kamohara Yoshinobu
• KAGEYU FUMIHITO
• UENO SHINJI
• GUO DANYI
• Tokumaru Yuki

Assignees

• 三菱自动车工业株式会社

Dates

Publication Date

20260508

Application Date

20210802

Priority Date

20200811

Claims (5)

1. 1. A belt transmission device is characterized by comprising: A crankshaft pulley fixed to a crankshaft of the internal combustion engine; an auxiliary machine pulley fixed to a rotation shaft of an auxiliary machine provided in parallel with the crankshaft; A belt wound around a plurality of pulleys including the crankshaft pulley and the auxiliary pulley, and A belt tensioner capable of swinging about a swinging shaft extending parallel to a rotation axis of the auxiliary pulley, a pair of tension pulleys being arranged in a circulating direction of the belt with the auxiliary pulley as a boundary, a plate spring connecting the pair of tension pulleys to each other, and applying tension to the belt, The pair of tension pulleys is provided with a line extending in a vertical direction through a swing shaft of the belt tensioner being sandwiched therebetween, the pair of tension pulleys being set such that a weight of any one of the pair of tension pulleys is heavier than a weight of any other tension pulley, so that it is difficult for any one of the pair of tension pulleys to be sprung up by the belt, The one of the tension pulleys is a tension pulley disposed downstream of the auxiliary pulley in a circulating direction of the belt.
2. 2. The belt transmission device according to claim 1, the auxiliary machine is a starter that drives the rotary shaft by supplying electric power at the time of starting the internal combustion engine.
3. 3. The belt transmission device according to claim 2, wherein a weight of the tension pulley disposed on the downstream side of the auxiliary pulley is set to be heavier than a weight of the tension pulley disposed on the upstream side of the auxiliary pulley in the circulation direction of the belt, so that the tension pulley disposed on the downstream side of the auxiliary pulley is less likely to pop up from the belt in the circulation direction of the belt.
4. 4. The belt transmission as recited in claim 3, wherein the plurality of pulleys further includes an upstream-side pulley provided on an upstream side of the auxiliary pulley in a circulating direction of the belt and a downstream-side pulley provided on a downstream side of the auxiliary pulley, The length of the belt from the auxiliary pulley to the downstream side pulley is longer than the length of the belt from the upstream side pulley to the auxiliary pulley, The one of the tension pulleys is disposed between the auxiliary pulley and the downstream pulley.
5. 5. A belt drive as claimed in any one of claims 1 to 3, the belt tensioner comprising: A first arm and a second arm respectively supporting the pair of tensioning pulleys, and A frame body fixed to the internal combustion engine and rotatably supporting the first arm and the second arm, respectively, The pair of tension pulleys respectively have a pulley body, a fastening member that mounts the pulley body to the first arm or the second arm, and a spacer provided between the pulley body and the fastening member, The thickness of the spacer of the any one of the tension pulleys is set to be thicker than the thickness of the spacer of the any other tension pulley so that the weight of the any one tension pulley is heavier than the weight of the any other tension pulley.

Description

Belt transmission device Technical Field The present invention relates to a belt drive. Background Patent document 1 discloses a belt transmission device provided with a crankshaft pulley fixed to a crankshaft of an internal combustion engine, an auxiliary pulley fixed to a rotation shaft of an auxiliary provided in parallel with the crankshaft, a belt wound around a plurality of pulleys including the crankshaft pulley and the auxiliary pulley, and a belt tensioner capable of swinging around the rotation shaft of the auxiliary pulley, and applying tension to the belt while disposing a pair of tension pulleys around the auxiliary pulley in a circulating direction of the belt. Prior art literature Patent literature Patent document 1 Japanese patent laid-open No. 2015-224613 Disclosure of Invention Technical problem to be solved by the invention In the belt transmission device disclosed in patent document 1, a belt is rapidly tensioned by an initial explosion of an internal combustion engine or the like, and when the tension pulley is sprung by the belt and the sprung tension pulley returns to the belt, a rattle is generated in the tension pulley. In view of the above, an object of an embodiment of the present invention is to provide a belt transmission device capable of suppressing rattle generated by a tension pulley. A belt transmission device according to an embodiment of the present invention includes a crankshaft pulley fixed to a crankshaft of an internal combustion engine, an auxiliary pulley fixed to a rotation shaft of an auxiliary provided in parallel with the crankshaft, a belt wound around a plurality of pulleys including the crankshaft pulley and the auxiliary pulley, and a belt tensioner capable of swinging around a swinging shaft extending in parallel with the rotation shaft of the auxiliary pulley, wherein a pair of tension pulleys are arranged in a circulating direction of the belt with the auxiliary pulley being defined, and tension is applied to the belt, and the weight of either tension pulley is set to be heavier than the weight of the other tension pulley, so that it is difficult for either tension pulley to be sprung up by the belt. According to the above configuration, even if the auxiliary pulley is abruptly tensioned on either the downstream side or the upstream side in the circulating direction of the belt, the belt is less likely to bounce off the tension pulley on either one, and the rattle generated on the tension pulley can be suppressed. In an embodiment of the present invention, any one of the tension pulleys having the above-described structure is a tension pulley disposed downstream of the auxiliary machine pulley in a circulating direction of the belt. In the circulating direction of the belt, the belt on the downstream side of the auxiliary pulley is easily tensioned when the revolution number of the internal combustion engine greatly fluctuates. According to the above configuration, even if the belt on the downstream side of the auxiliary pulley is suddenly tensioned in the circulating direction of the belt, the tension pulley is less likely to be sprung up by the belt on the downstream side of the auxiliary pulley, and the rattle generated in the tension pulley can be suppressed. In an embodiment of the present invention, in the above configuration, the auxiliary machine is a starter that drives the rotary shaft by supplying electric power at the time of starting the internal combustion engine. When the internal combustion engine is started, electric power is supplied to drive a rotation shaft of an auxiliary machine (motor generator), so that a belt on an upstream side of an auxiliary machine pulley (MG pulley) is tensioned and a belt on a downstream side thereof is loosened in a circulating direction of the belt. After that, since the crankshaft starts to rotate by the initial explosion of the internal combustion engine, the belt on the downstream side of the auxiliary pulley (MG pulley) is rapidly tensioned in the circulating direction of the belt, and therefore the tensioning pulley on the downstream side of the auxiliary pulley is liable to spring up. In addition, in a state where rotational torque of the crankshaft pulley is transmitted to the auxiliary machine pulley (MG pulley) through the belt, the belt on the downstream side of the auxiliary machine pulley (MG pulley) is tensioned and the belt on the upstream side is relaxed in the circulating direction of the belt. Then, when the rotation of the crankshaft pulley is assisted by the auxiliary machine (motor generator), the belt on the upstream side of the auxiliary machine pulley (MG pulley) is rapidly tensioned in the circulating direction of the belt, and therefore the tension pulley on the upstream side of the auxiliary machine pulley is liable to pop up. That is, the pair of tension pulleys disposed with the motor generator as a boundary are easily sprung up by the belt. According to the above configuration