JPH08184358A - Chain tension device - Google Patents

Abstract

PURPOSE: To perform excellent tension of a chain and to perform smooth chain transmission by a method wherein the free end part of a chain tension tool is slidably supported by a tension guide having a guide surface formed integrally with a regulation part. CONSTITUTION: A chain tension tool 6 positioned facing the outside of a chain 8 stretched between a pair of chain gears 4a and 5a comprises a resilient plate curved in a bow-form manner. The side end part thereof is attached to a body 1, the slide contact part 6b of the other end being a free end is slidably supported by the guide surface of a stretch guide 7. A guide surface has width increased to a value higher than that of the slide contact part 6b of the chain tension tool 6 and is formed in a recess. By integrally forming a narrow regulating part, the roller of the chain 8 is brought into contact therewith for regulation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chain tensioning device for transmitting a chain tension by installing a chain tensioner on the outside of a chain stretched around a pair of chain gears.

[0002]

2. Description of the Related Art Conventionally, a chain tensioning device for a chain transmission in which a chain tensioner is provided to a chain stretched around a pair of chain gears in a chain case has been disclosed in Japanese Utility Model Laid-Open No. 48-19881.
This chain tensioning device is well known in Japanese Patent Publication No. JP-A-2003-242242, and one end of the chain tensioner made of an elastic plate curved in an arc shape is supported by the main body, and the free end of the other end is used as a tension guide. By slidably inserting and supporting the insertion portion, the chain is tensioned in response to looseness due to elongation of the chain and the runout of the chain tensioner is regulated.

[0003]

The known chain tensioning device described above merely inserts the free ends of the chain tensioners into the upper and lower tension guides, and supports the free ends in the tension direction. Although the regulation of lateral fluctuation is insufficient, the chain easily shakes and the tension guide does not regulate the roller part of the chain in the state of being close to the chain gear. It is not possible to properly respond to changes in chain tension due to fluctuations in rotation, etc., making it difficult to accurately prevent chain pulsation and making smooth transmission difficult, and causing the chain to contact the inner wall of the chain case There was a problem of causing. Therefore, the present invention solves the above-mentioned conventional problems, and properly supports the chain tension by slidably supporting the free end portion of the chain tensioner with a tension guide integrally formed with a guide surface and a regulation portion. It is an object of the present invention to provide a chain tensioning device that can perform the chain transmission well.

[0004]

SUMMARY OF THE INVENTION A chain tensioning device of the present invention for solving the above-mentioned conventional problems is provided on the outer side of a chain stretched on a pair of chain gears, and the chain tensioning of the chain is performed. The chain tensioner to be performed is formed by an elastic plate curved in an arc shape with one end attached to the main body, and the sliding contact part at the other end, which is a free end, can slide on the tension guide. In the chain transmission device that receives and supports the chain tensioner, the guide surface of the tension guide that receives the sliding contact portion of the chain tensioner is formed to be wider than the sliding contact portion and is recessed to form a side portion of the chain tensioner. The runout of the chain is regulated and the chain is stretched.

Further, the tension guide is formed in a laterally equiangular hem-shaped guide surface, and a narrow restricting portion capable of contacting the roller of the chain is integrally formed on the guide surface. Is characterized by.

Further, it is characterized in that the restriction portion formed on the guide surface of the tension guide is installed close to the chain gear.

[0007]

With the above structure, when the chain 8 rotates, the chain tensioner 6 that comes into contact with the slack side has its free end slidable contact portion 6b so that the bending radius is increased by the urging force of the elastic plate.
1 slides on the tension guide 7 in the direction of the solid line arrow in FIG. 1 to bulge toward the chain side and appropriately tension the chain 8, and
On the tension side, the chain 8 is pressed by the tension of the chain 8, and the sliding contact portion 6b is slid on the tension guide 7 in the direction of the dotted arrow to be transformed into an extended posture, and the chain 8 is pressed to enable smooth chain driving. To do. At this time, the sliding contact portion 6b slides while being regulated by the guide surface 70 of the tension guide 7 to the proper position for chain tensioning, so that the chain tensioning tool 6 is always maintained in the central portion of the tension guide 7 and a good chain tensioning action is maintained. It can be performed. Further, since the regulating portion 71 connected to the guide surface 70 regulates the roller 81 of the chain 8 in contact with it, contact between the chain 8 and the chain case 3 can be prevented and smooth transmission can be performed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. A chain case 3 consisting of a main body 1 and a lid 2 is shown in FIG.
The chain 8 is wound around a pair of chain gears 4a, 5a for transmitting power from the input shaft 4 to the output shaft 5, which is mounted as a chain transmission device of the tiller A equipped with a tractor as shown in FIG. The chain tensioner 6 is supported on both outer sides of the chain 8 by tensioning guides 7 so that the chain tensioning force can be transmitted. The chain case 3 forms a housing by fastening a large number of mounting hole portions formed on the flange surface of the outer periphery of the main body 1 and the lid 2 with a fixture K composed of bolts and nuts, and further from the main body 1 The plurality of protruding brackets 1a are fixed to the main body of the tiller A by screwing.

On the other hand, one end of the input shaft 4 driven from the transmission case 10 of the tiller A has a flange 11a of the upper support pipe 11 projecting leftward from the transmission case 10.
In addition, the output shaft 5 is supported by a bearing 1f provided in a support plate 1e fixed by a bolt 11b, and the output shaft 5 is supported by a bearing 1g provided below the main body 1 and the lid 2. The number of teeth of the chain gear 4a fixed to the input shaft 4 is smaller than the number of teeth of the chain gear 5a fixed to the output shaft 5, so that the power is reduced in the chain case 3 and transmitted to the output shaft 5. At the end of the output shaft 5, one end of the cultivating shaft 50 in which a large number of cultivating claws 51 are planted is connected and supported.

The input shaft 4 and the output shaft 5 on the main body 1 side
At the middle part of the chain 8, chain tensioners 6, 6 are provided opposite to each other on both outer sides of the chain 8, and the chain tensioner 6 is composed of an elastic body curved in an arc shape protruding inward. An annular portion 6a formed at one end thereof is provided with two pins 60, 60 which are planted in a portion facing each other in the vicinity of the input shaft 4 on the main body 1 side.
Each of the pins 60 is loosely fitted and supported, and the tip of the pin 60 is axially fixed by a stopper T including a washer and a split pin. Further, the chain tensioner 6 has a sliding contact portion 6b formed by bending a folded portion at the other end which is a free end, and the sliding contact portion 6b is formed.
Between the chain link 5 constituting the chain 8 by the tension portion 6c of the chain tensioner 6 by allowing the tension guides 7, 7 formed on the main body 1 to slidably receive and support the chain gear 5a. The rollers 81 are pressed against each other with an appropriate pressure so that the chain tension transmission of the chain 8 is performed well.

That is, although the tension guide 7 will be described in detail later, the tension guide 7 is configured as shown in FIGS. 1 to 3 so that the tension guide 7 is loosened due to the elongation of the chain 8 or loosened at the beginning of starting at the time of forward / reverse switching rotation, and the tiller shaft. In the case where the chain 50 swings largely due to intermittent overload of 50, the chain 8 is prevented from steadying by the chain tensioner 6, so that the chain 8 does not contact the chain case 3. , Good guidance and smooth transmission.

The tension guide 7 in this embodiment has a wide guide surface 70 that receives both sides of the sliding contact portion 6b of the chain tensioning tool 6 in a plan view and guides it slidably, and a narrow restricting portion 71 connected to this. Are integrally formed into a T-shape, and extend toward the lower side of the chain 8 in each of the forward and reverse rotation directions to a position close to the chain gear 5, so that the chain 8
The roller 81 is guided and regulated so that the chain link 80 does not largely swing and come into contact with the chain case 3 when it is loosened. Also, this tension guide 7
The side portion of the chain tensioner 6 is swung to the side by supporting the both edges of the slidable contact portion 6b on both sides of its inner surface by forming a curved V-shape with its central portion recessed in a side view. Is configured to keep the chain tensioning tool 6 slidably contacting the central portion of the tensioning guide 7, and to satisfactorily press and guide the roller 81 slid at the tensioning portion 6c of the tensioning guide 7. ing.

As shown in FIG. 3, the tension guide 7 is formed so as to be recessed at an equal angle in a side view, and one side surface side of the tension guide 7 should be attached to the inner surface of the side wall 1h on the main body 1 side so as to form a flat joint. Thus, the cover 2 can be stably fixed, and the cover 2 can be fitted and assembled from the side. Further, as shown in FIG. 4, the main body 1 is attached to the non-contact surface side of the tension portion 6c of the chain tensioner 6.
The restricting members 61 supported by the mounting shafts 60 that are erected on the side are provided in pairs, and the restricting members 61 make the protruding ridges 62 that contact the non-contacting surface side of the chain tensioner 6 elastic. When the chain 8 is going to bend the chain tensioner 6 by a predetermined amount or more as shown in FIG. However, further inflection is regulated to prevent a large swing of the chain 8 and damage of the chain tensioner 6.

Reference numeral 65 denotes an interposition member which is loosely fitted to the support column 66 and sandwiched between the main body 1 and the cover 2.
5 is made of rubber or a plastic material and is formed into a resilient tubular shape whose length is longer than the inner wall interval of the chain case 3 by about several millimeters, and is compressed between the main body 1 and the lid 2. By wearing the chain case, resonance of the chain case 3 is suppressed and vibration and noise are prevented. Also,
By applying an adhesive elastic coating member 67 to the inner surface of the chain case 3, the resonance frequency in the chain case 3 may be varied to produce a sound absorbing effect.

Next, the cultivating apparatus A provided with the chain case 3 constructed as described above in FIG. 5 will be described. As described above, the chain case 3 is fixed to the support pipe 11 for internally supporting the input shaft 4 projecting leftward from the transmission case 10, while the support pipe 12 projecting rightward to the transmission case 10 is fixed. Inside, a free-standing shaft 13 for a balancer is internally supported via a bearing 13a, and a support frame 14 for axially supporting the other end of the cultivating shaft 50 is fixed to the end thereof. The idle shaft 13 is set to have substantially the same weight as the input shaft 4, and the small bevel gear 10b fixed to the end of the drive shaft 10a is attached to the bevel gears 4b and 13b provided at the opposite shaft ends of the shafts 4 and 13, respectively. By engaging with each other, the input shaft 4 and the idle shaft 13 are simultaneously rotated.

As a result, the side rotary type cultivating device A for transmitting the chain of the cultivating shaft 50 on one side of the machine body has the left and right rotating shafts having substantially the same weight, and the left and right balances of the machine body are rotated by rotating the rotating shafts. The above-mentioned tilling shaft 50 can be improved.
In addition to suppressing the sway of the airframe during the idling, the rotary inertia moment can be increased, and the cultivating shaft 50 can be stably rotated for high-performance cultivating work without causing arrhythmic rotation.

Further, rod-like heavy hangings 55 for a rotary balancer are detachably attached to the holders 56 fixed to the cultivating shaft 50 inside both ends of the cultivating shaft 50 made of a tubular member. The rotation balance of the tilling shaft 50 having the tilling claw 51 can be well balanced, and when uneven wear of the tilling claw 51 occurs, or when the above-mentioned tilling shaft 50 is equipped with an extended tilling shaft, By removing the cultivating shaft 50 and attaching the hanging 55 having an appropriate weight to the holder 56, the cultivating shaft 50 can be smoothly rotated. Further, since the heavy drip 55 having the above-mentioned configuration is provided inside the cultivating shaft 50 without being mounted on the outside of the cultivating shaft 50 unlike the conventional one, it is possible to prevent adhesion of mud and weeds and the like. It has the characteristic of performing work.

In the cultivating work by the cultivating apparatus A constructed as described above, the input shaft 4 and the output shaft 5 are normally rotated and the chain 8 is rotated.
When a load is applied to the chain 8, as shown in FIG. 1, the upper side of the chain 8 in the chain case 3 becomes the tension side and the lower side becomes the slack side. Among them, the chain tensioner 6 abutting on the slack side largely slides on the tension guide 7 in the direction of the solid line so that the sliding contact portion 6b at the free end slides on the tension guide 7 so as to increase the bending radius by the urging force. Then, the tensioned portion 6c tensions the chain 8 to an appropriate pressure to perform a favorable chain transmission.

On the other hand, the chain tensioner 6 that abuts the tension side
Is pressed by the tension of the chain 8 and its sliding contact portion 6b slides on the tension guide 7 in the direction of the arrow dotted line,
By deforming the chain 8 to the extended position up to the position where it is restricted by the restricting member 61 and tensioning the chain 8, the chain 8 can be smoothly driven without a great resistance. In addition, this chain drive is used for input shaft 4 to output shaft 5
When the chain 8 is reversed in the direction and a load is applied to the chain 8, the reverse of the figure is that the lower side of the chain case 3 is the tension side and the upper side is the slack side, which is a smooth reverse chain as described above. By driving, the forward / reverse switching rotary tilling work of the tiller shaft 50 can be favorably performed.

At this time, the guide surface 70, which is formed by recessing the wide width of the tension guide 7 at equal left and right angles, receives both sides of the slide contact portion 6b of the chain tension tool 6 and guides the chain tension by sliding. 6 can always be regulated and maintained at the central portion of the tension guide 7, and the chain tensioning tool 6 abuts on the roller 81 between the chain links 80 to perform a favorable chain tensioning action. Further, the narrow restricting portion 71 connected to the guide surface 70 is loosened due to the elongation of the chain 8, or when the tiller shaft 50 is intermittently overloaded and the chain 8 vibrates greatly, and When the swelling reaction of the wrapping portion on the side of the chain gear 5 occurs in the initial stage of the switching start in which the gear 8 is rotated in the normal and reverse directions, the roller 81 portion is accurately contacted and regulated, and the chain link 80 of the chain 8 is connected to the chain case 3.
It is possible to prevent a problem such as a violent collision with the inner wall of the chain, to smoothly perform smooth chain transmission, and to prevent noise and breakage of the chain case 3. Further, this portion can be used as an extension portion of the slide allowance of the tension guide 7. In this case, the sliding contact portion 6b of the tension guide 7 is brought closer to the chain gear 5 to further prevent the chain 8 from steadying. Can be improved.

[0021]

The present invention configured as described above can achieve the following effects. According to the first aspect, the chain tensioner is slidably guided in the state where the sliding contact portion formed as the free end is restricted from lateral deflection by the guide surface of the tension guide, so that the chain tensioner is maintained in a stable posture. The chain can be appropriately stretched according to the elongation of the chain, smooth chain transmission can be favorably performed, and a chain tensioning device having a simple structure can be provided.

According to the second aspect of the present invention, the chain tensioner can be maintained at the center of the guide surface of the tension guide to properly tension and guide the chain, and the roller of the chain can be abutted and regulated by the narrow regulation portion. Therefore, in the case where the chain is stretched, the slack of the chain can be regulated and the chain can be stretched with high performance.

According to the third aspect of the present invention, the tension guide can be satisfactorily tensioned with the chain by providing the guide surface and the regulating portion integrally with each other and bringing them as close as possible to the chain gear. It is possible to accurately control the slack of the chain part wound around the chain and smoothly perform the chain transmission without contacting the chain with the chain case.

[Brief description of drawings]

FIG. 1 is a side view showing a chain transmission device during normal rotation.

FIG. 2 is a plan view showing a configuration of a tension guide.

FIG. 3 is a side view of FIG.

FIG. 4 is a sectional view taken along the line AA of FIG.

FIG. 5 is a cross-sectional view showing a transmission structure of the tiller.

[Explanation of symbols]

 1 main body 2 lid 3 chain case 4 input shaft 5 output shaft 4a chain gear 5a chain gear 6 chain tensioner 6b sliding contact part 7 tension guide 8 chain 70 guide surface 71 regulation part 81 roller 82 chain link A cultivator

Claims (3)

[Claims] 1. A chain tensioner, which is provided on the outside of a chain stretched on a pair of chain gears and tensions the chain, is arcuate with one side end attached to the main body. In a chain transmission device that is formed of an elastic plate that is curved in a vertical direction and that slidably receives and supports a sliding contact portion at the other end that is a free end, in a tension guide that receives the sliding contact portion of the chain tensioner. A chain tensioning device, wherein the guide surface is formed to be wider than the sliding contact portion so as to be recessed so as to restrict the lateral deflection of the chain tensioner to perform the chain tensioning. 2. A tension guide is formed on a laterally equiangular hemispherical guide surface in side view, and a narrow restricting portion capable of contacting a roller of a chain is integrally formed on the guide surface. Item 1
The described chain tensioning device. 3. The chain tensioning device according to claim 1, wherein the restricting portion formed on the guide surface of the tension guide is installed close to the chain gear.