JP2011106497A - Tensioner device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tensioner device, in which a piston rod is extended from a body having a damper mechanism therein, for pressing a chain wound around both sprockets or a pulley of a general machine, or a span of a belt. <P>SOLUTION: The body 2 is attached to a bracket 1 which can be fixed to a machine device, a slider 4 is attached to a tip of a piston rod 3, guide rails 5, 5 for sliding the slider 4 are disposed to the bracket 1, and the sprocket 6 or the pulley is rotatably attached to the slider 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a mechanical tensioner device that prevents loosening of a transmission chain.

  When power is transmitted by being wound around a sprocket, a chain formed by connecting a plurality of links wears at a connecting portion of each link and generates elongation. If it is a roller chain that is exposed and wound around to drive the rear wheel of a motorcycle, it is possible to cope with the elongation by adjusting the position of the sprocket. In the case of a chain, a tensioner device is attached to prevent the chain from being stretched due to elongation and the over-tension accompanying the butter.

That is, the timing chain is wound so that the camshaft forming the cam for opening and closing the crankshaft of the engine and the intake valve and the exhaust valve can rotate in synchronization with each other, and as the timing chain extends, Thus, a tensioner device is mounted so as not to cause a phase difference in the rotation of each shaft.

  FIG. 6 shows a conventional general tensioner device mounted inside an engine. A housing (A) and a plunger (B) are slidably provided in the housing (A), and hydraulic oil is supplied from the outside. When (c) is fed into the oil chamber (d), the plunger (b) protrudes through a coil spring (e) built in the oil chamber (d). Therefore, moderate tension is applied to the chain (f) slackened by pushing up the tensioner lever (ra) that swings about the shaft (na), and conversely when a large tension acts on the chain (f). The check valve closes to prevent the plunger (b) from moving backward. In this way, the chain (f) is placed in a state where a moderate tension is always applied.

  By the way, the tensioner device shown in the figure is for a timing chain mounted in a car engine, and there is a problem in targeting a general machine. Of course, by attaching this tensioner device, it is possible to prevent fluttering along with chain elongation. However, in the case of a chain of a general machine where very large tension and load are applied, It lacks durability.

  There are various conventional techniques as a tensioner device. For example, a “tensioner device” disclosed in Japanese Patent Application Laid-Open No. 2004-144189 is provided with a torsion coil spring attached to a shaft of a tensioner lever that swings about a shaft so that the chain does not loosen. A tensioner device that applies a predetermined tension by urging the lever with a spring force, and prevents the lever from returning and swinging against a large impact acting on the chain.

A “chain tensioner” according to Japanese Patent Laid-Open No. 10-196745 is a tensioner device that is attached to prevent fluttering associated with elongation of a chain used in a general machine.
The chain tensioner is designed to eliminate looseness by pushing the chain spanned over the sprocket, and this chain tensioner is integrated with a contact surface having an arc surface that contacts the chain, and the contact surface. The contact portion is connected to one end of the support portion, and an engagement recess is formed on the support portion at a predetermined interval on the opposite side of the support portion. A support member for the chain tensioner is disposed on the side.
"Tensioner device" according to Japanese Patent Application Laid-Open No. 2004-144189 "Chain tensioner" according to JP-A-10-196745

  As described above, various tensioner devices are known. The present invention is directed to a tensioner device that is attached to a general machine on which a large load acts and prevents fluttering due to chain elongation, and provides a tensioner device that can be easily attached to any machine.

  The tensioner device of the present invention is intended for general machines, not mounted in the engine of a vehicle, and rotatably supports an idler sprocket that can mesh with the chain. The idler sprocket is in accordance with the tension of the chain. It is configured to move forward and backward. Here, the general machine is a machine tool, a transport machine such as a conveyor, a production machine, and the like, and is intended for machines other than vehicles, and is not specifically limited.

  As a power transmission means, not only a chain but also a belt is an object. If the belt is used, a pulley is rotatably supported instead of a sprocket. In addition, a lever or a pressing member that is pressed against a chain or a belt as shown in FIG. 6 may be used instead of an idler sprocket or pulley. By the way, a piston rod is extended from the main body, a slider is attached to the tip of the piston rod, and the slider is guided so as to move along a guide provided in parallel with the piston rod.

  The main body incorporates an oil damper mechanism inside the cylinder, and the piston rod extends from the piston. A stopper is provided at an intermediate portion in the cylinder to restrict the rise of the piston, but a spring is incorporated to urge a spring force to raise the piston. Further, hydraulic oil is filled under the piston of the main body.

  An auxiliary piston is provided on the upper side of the stopper, leaving a space filled with hydraulic oil, and a spring is built in the upper side of the auxiliary piston to urge the auxiliary piston. By the way, if a large tension is applied to the chain, a force for retreating the idler sprocket engaged with the chain acts, but it is supported by the hydraulic oil filled in the lower cylinder of the piston, resulting in a large resistance. Here, the hydraulic oil flows through a very small gap between the piston and the cylinder so as to enter the space above the stopper. However, the piston once retracted rises smoothly by the spring force of the spring.

  The tensioner device of the present invention is attached to a bracket, and a guide for moving a slider is provided on the bracket. The main body is fixed to the bottom plate of the bracket. The main body is fitted into a hole penetrating the bottom plate, and two nuts are screwed into a screw portion formed on the outer periphery of the main body, and the bottom plate is sandwiched between both nuts. The body is fixed. Therefore, the structure of the body can be adjusted by loosening the nut.

  The tensioner device of the present invention has a sturdy structure, and therefore can be used as a chain tensioner device for a general machine where a large load acts, and can be easily installed anywhere via a bracket. And since the oil damper mechanism is built in the main body, when a large load acts on the sprocket, pulley or lever attached to the tip of the piston rod extending from the main body, the load can be supported. .

On the other hand, the vibration of the chain or belt is suppressed by the oil damper mechanism of the main body, and stable power transmission with less vibration is performed. Furthermore, the position of the sprocket, pulley, or lever attached to the piston tip can be adjusted by loosening the nut on the main body attached to the bracket, and fine adjustment of the tension acting on the chain or belt can be easily performed.

The front view which shows the tensioner apparatus which concerns on this invention. The side view which shows the tensioner apparatus which concerns on this invention. Damper mechanism inside the body. When a pulley is attached to the slider. The tensioner device according to the present invention. Conventional tensioner device.

  1 and 2 show an embodiment of a tensioner device according to the present invention. FIG. 1 is a front view and FIG. 2 is a side view. In the figure, 1 is a bracket, 2 is a main body, 3 is a piston rod, 4 is a slider, 5 is a guide rail, and 6 is an idler sprocket. A shaft screw 7 extends from the slider 4, and a bush 8 is fitted to the shaft screw 7, and the idler sprocket 6 is rotatably attached to the bush 8 via a bearing. That is, the idler sprocket 6 is attached to the shaft screw 7 and screwed into the screw hole of the slider 4.

  The bracket 1 is formed in a U shape having an upper plate 9, a side plate 10, and a lower plate 11. It has been. Therefore, the slider 4 has guide holes formed on both sides thereof, and guide rails 5 and 5 are fitted in the guide holes, and the slider 4 can move in the vertical direction along the guide rails 5 and 5. Accordingly, the idler sprocket 6 attached to the slider 4 also moves in the vertical direction.

  The main body 2 forms a cylindrical cylinder, and a screw portion 12 is provided on the outer periphery at the lower end portion, and two nuts 13 and 13 are screwed and attached to the screw portion 12. Therefore, the main body 2 is attached to the lower plate 11 of the bracket 1, and a hole is passed through the lower plate 11, and the screw portion 12 of the main body 2 is fitted into the hole, and both nuts 13, 13 is tightened. Accordingly, the main body 2 stands and is fixed vertically with respect to the lower plate 11, and the slider 4 is connected to the tip of the piston rod 3 extending from the main body 2.

  A piston is provided inside the main body 2, and a piston rod 3 extends from the piston. The inside of the main body 2 constitutes a damper mechanism that restricts the vertical movement of the piston. The idler sprocket 6 meshes with a chain wound around the drive side sprocket and the driven side sprocket. When an overload acts on the chain and the tension increases rapidly, the idler sprocket 6 is pushed down and moves backward. However, the damper mechanism of the main body 2 can exert a large resistance to retreat and prevent the chain from fluttering.

  FIG. 3 is a specific example showing the internal structure of the main body 2. A piston 14 is provided inside the main body 2 of the cylindrical cylinder, and the piston 14 is attached to the lower end of the piston rod 3. A coil spring 15 is accommodated on the lower side of the piston 14 to bias the spring force that pushes up the piston 14. However, the main body 2 is provided with a stopper 16, and the stopper 16 is prevented from rising by a C ring 17 (retaining ring) that is fixedly fitted in a groove formed on the inner surface.

  On the other hand, another auxiliary piston 19 is provided above the stopper 16 so as to move up and down with a predetermined space 18 therebetween. A packing 20 is attached to the outer periphery of the auxiliary piston 19 to eliminate a gap with the inner peripheral surface 25 of the main body 2, and a packing 21 is also attached to the inner periphery to connect the piston rod 3. The gap is eliminated. That is, the auxiliary piston 19 has a ring shape, and the piston rod 3 is inserted through the central hole that passes therethrough. However, the auxiliary piston 19 can move up and down independently of the movement of the piston rod 3.

  A housing 22 is attached to the upper end of the main body 2 and is fixed so as not to be lifted and removed by a C ring 23 fixed to the inner peripheral surface, and an O ring 24 is provided on the outer periphery. A gap with the peripheral surface 25 is eliminated. By the way, the lower space 30 of the piston 14 is filled with the working oil 26, and the working oil 26 is also filled in the space 18 formed between the stopper 16 and the auxiliary piston 19. A coil spring 27 is accommodated between the housing 22 and the auxiliary piston 19, and the spring force of the coil spring 27 acts to push down the auxiliary piston 19.

  By the way, when a large load acts on the idler sprocket 6, the piston rod 3 tends to be pushed down, but the piston 14 is supported by the hydraulic oil 26 filled in the space 25. A boss 28 is attached to the lower end of the piston rod 3, and a valve (not shown) is attached to the boss 28. The specific structure of the valve is not limited, but is closed so as to prevent the piston rod 3 from being lowered. However, when it rises, it opens and hydraulic oil 26 can flow smoothly. For example, the valve structure is a combination of a coil spring and a ball, and when the ball is lowered, the ball closes the inlet with the urging spring force. It can be made to flow.

  However, if the hydraulic oil 26 in the space 25 does not flow at all, there is no lowering of the piston rod 3 and an excessive tension is applied to the chain. Therefore, the space between the inner peripheral surface of the spacer 31 fitted in the main body 2 and the piston 14 The hydraulic oil 26 can flow through a very small gap formed in the upper space 18 of the stopper 16. In this case, the hydraulic oil 26 that flows into the upper space 18 of the stopper 16 as the piston 14 descends pushes up the auxiliary piston 19. That is, since the piston rod 3 is present above the stopper 16, the auxiliary piston 19 must be raised in order to accommodate the flowing hydraulic oil 26.

  Once the piston 14 that has been pushed down has a small load acting on the sprocket 6, the spring force of the coil spring 15 accommodated in the lower space 25 of the piston 14 acts and the piston 14 is pushed. Raised. At this time, the valve provided in the boss 28 is opened, and the hydraulic oil 26 in the space 18 can flow into the space 25 through the valve. Accordingly, the auxiliary piston 19 is also pushed down by the spring force of the coil spring 27 at the same time.

  FIG. 4 shows a case where a pulley 29 is attached to the shaft screw 7 instead of the sprocket 6. In the case of a power transmission device using a belt, the pulley 29 is used. Furthermore, there may be a structure in which a tensioner lever capable of sliding on the chain is pressed instead of the sprocket 6 or the pulley 29. In this case, as shown in FIG. 5, the intermediate portion of the tensioner lever that swings with the shaft stopped is pressed by the piston rod 3. Alternatively, it is possible to attach a pressing member to the tip of the piston rod instead of the swinging lever.

  FIG. 5 shows another embodiment of the tensioner device according to the present invention. In the tensioner device shown in FIGS. 1 and 2, when the idler sprocket 6 is attached so as to mesh with the chain, FIG. 4 shows the case where the pulley 29 is attached to prevent the belt from fluttering. In contrast, in FIG. 5, the pressing member 32 is attached to the slider 4.

  The upper surface 33 of the pressing member 32 forms a smooth convex curved surface, and the chain 34 can travel along the upper surface. That is, as the roller 35 rotates, the chain 34 travels along the upper surface 33 of the pressing member 32, and an appropriate tension is applied to the chain 34. Here, the internal structure of the main body 2 is the same as that in the above embodiment.

1 Bracket 2 Body 3 Piston rod 4 Slider 5 Guide rail 6 Idler sprocket 7 Shaft screw 8 Bush 9 Upper plate
10 Side plate
11 Lower plate
12 Screw part
13 Nut
14 Piston
15 Coil spring
16 Stopper
17 C-ring
18 space
19 Auxiliary piston
20 Packing
21 Packing
22 Housing
23 C-ring
24 O-ring
25 Inner surface
26 Hydraulic oil
27 Coil spring
28 Boss
29 pulley
30 spaces
31 Spacer
32 Press member
33 Top view
34 chain
35 Laura

Claims (4)

In a tensioner device in which a piston rod is extended from a cylinder type main body provided with a damper mechanism to press a chain or belt span wound around both sprockets and pulleys, the main body may be fixed to a mechanical device. It is attached to a bracket that can be mounted, a slider is attached to the tip of the piston rod, a guide rail for sliding the slider is provided on the bracket, and an idler sprocket or pulley is rotatably attached to the slider Tensioner device. In a tensioner device in which a piston rod is extended from a cylinder type main body provided with a damper mechanism to press a chain or belt span wound around both sprockets and pulleys, the main body may be fixed to a mechanical device. It is attached to a bracket that can be mounted, a slider is attached to the tip of the piston rod, a guide rail for sliding the slider is provided on the bracket, and an idler sprocket or pulley is rotatably attached to the slider. A piston that extends the piston rod is provided in the interior, and a stopper is attached to an intermediate portion to regulate the protruding amount of the piston rod, and a spring force that causes the piston rod to protrude is provided in the tip side space partitioned by the stopper. Energizing coil spring The piston rod side space that is accommodated and filled with hydraulic oil is provided with another auxiliary piston, and a coil spring is accommodated to energize the spring force to push down the auxiliary piston, and Fill the space between the auxiliary piston and the stopper with hydraulic oil, and prevent the flow of hydraulic oil when the piston rod moves backward and allow the flow when the piston rod moves forward to the part where the piston is installed. A tensioner device characterized in that a valve that operates is attached to the tensioner device. The tensioner device according to claim 1 or 2, wherein a lever or a pressing member on which a chain or a belt travels is attached to the slider instead of the sprocket or the pulley. The bracket is U-shaped, and the main body is fitted into a hole provided in the lower plate, and the lower plate is sandwiched by two nuts screwed into the threaded portion of the main body to attach the main body to the bracket. The tensioner device according to claim 2 or claim 3.

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