JP3573732B2 - One-way drive link mechanism - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a link mechanism in which an action point is always displaced only in one of a forward direction and a reverse direction even when a force point is displaced in a forward direction and a reverse direction along a predetermined direction.
[0002]
2. Description of the Related Art
Conventionally, the principle of leverage is well known, and a link mechanism using this principle has been applied to various technical fields. The principle of leverage is that when the point of force is displaced, the point of action is displaced about the fulcrum in the direction opposite to the direction of displacement of the point of force. The acting force can be amplified and transmitted to the point of action, or the displacement of the point of force can be amplified and transmitted to the point of action.
[0003]
By the way, when applying the principle of leverage, there is a case where it is desired to displace the action point in one direction regardless of the direction of displacement of the force point. For example, in a control device of a double tilt type swash plate type hydraulic pump, even if a swash plate connecting portion as a power point is displaced to both left and right, the regulator sleeve as an action point is driven only in one direction. However, in this case, a link mechanism for displacing the action point in one direction regardless of the direction of displacement of the force point is required.
[0004]
Therefore, an object of the present invention is to provide a link mechanism in which the action point is always displaced only in one of the forward direction and the reverse direction even when the force point is displaced in the forward direction and the reverse direction along the predetermined direction. It is to be.
[0005]
[Means for Solving the Problems]
(1) In order to achieve the above object, the inventor of the present application can apply two levers to form a so-called double lever while applying the principle of leverage, regardless of the moving direction of the force point. It is noted that the point of action can always be moved only in one direction.
[0006]
(2) Therefore, the one-way drive link mechanism according to the present application is provided with a first fulcrum member and a second fulcrum member fixedly arranged at a predetermined interval, and between the first fulcrum member and the second fulcrum member. A first engaging portion rotatably supported by the support shaft and capable of engaging with the first fulcrum member by rotating about the support shaft, and a first engagement portion capable of engaging with the second fulcrum member. and have a arm member and are formed second engaging portions, said when said arm member is the first engagement portion is rotated about the support shaft is engaged with said first fulcrum member The arm member rotates when the arm member rotates about the first fulcrum member and the arm member rotates about the support shaft and the second engagement portion engages with the second fulcrum member. Are configured to rotate about the second fulcrum member as a fulcrum. You. The first and second engagement portions are formed in a hole shape, and the first fulcrum member is loosely inserted into the first engagement portion, and the second fulcrum member is loosely inserted into the second engagement portion. Preferably, it is inserted.
[0007]
According to this configuration, the first fulcrum member and the second fulcrum member are fixedly arranged at a vertical position, for example, in the vertical direction, and the support shaft is arranged between the first fulcrum member and the second fulcrum member. When the arm member is rotated clockwise about the support shaft, the second engagement portion engages with the second fulcrum member. When the arm member is further rotated clockwise, the second fulcrum member is rotated. Constitute a fulcrum, and the arm member rotates clockwise about the second fulcrum member. Since the second fulcrum member is located below the support shaft, the support shaft moves rightward when the arm member rotates clockwise about the second fulcrum member as a fulcrum.
[0008]
On the other hand, when the arm member is rotated counterclockwise about the support shaft, the first engagement portion engages with the first fulcrum member. However, when the arm member is further rotated counterclockwise, The first fulcrum member forms a fulcrum, and the arm member rotates counterclockwise around the first fulcrum member. Since the first fulcrum member is located above the support shaft, the support shaft moves rightward when the arm member rotates counterclockwise about the first fulcrum member as a fulcrum.
[0009]
(3) An urging member that elastically urges the support shaft in a direction in which the first fulcrum member and the second fulcrum member abut on the arm member may be provided.
[0010]
With this configuration, the arm member always comes into contact with at least one of the first fulcrum member and the second fulcrum member, so that the support shaft can be stabilized.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention can be applied to various technical fields. For example, FIG. 3 is a diagram schematically showing a feedback mechanism employed in a regulator for a hydraulic pump, and the one-way drive link mechanism according to the present invention can be applied to this feedback mechanism.
[0012]
Referring to FIG. 1, this one-way drive link mechanism 1 is employed in a regulator of a double tilt type swash plate type hydraulic pump, and even if the tilt angle of the swash plate changes in any direction ( Even if the control lever 2 changes in any direction of the arrows 2 and 3), the feedback sleeve 4 for feeding back the change of the swash plate tilt angle can be moved only to the right side in the figure. The one-way drive link mechanism 1 is connected to the control shaft 5, a support shaft 6 for rotatably supporting the control lever 5, a first fulcrum member 7 and a second fulcrum member 8, and the support shaft 6. Feedback sleeve 4. The control lever 5 is provided with through holes 9 and 10, through which the first fulcrum member 7 and the second fulcrum member 8 are inserted.
[0013]
Assuming that the control lever 5 is displaced clockwise (in the direction of arrow 3) from the first state (the state shown by the solid line), the second fulcrum member 8 rotates as a fulcrum. Therefore, the support shaft 6 moves to the right. On the other hand, if the control lever 5 is displaced in the counterclockwise direction (the direction of arrow 2) from the first state (the state shown by the solid line), the first fulcrum member 7 rotates as a fulcrum. Therefore, the support shaft 6 moves to the right.
[0014]
At this time, the ratio (d1 / d2) of the distance d1 from the tip 11 of the control lever 5 to the second fulcrum member 8 and the distance d2 from the second fulcrum member 8 to the support shaft 6, and the tip of the control lever 5 If the ratio (d3 / d4) of the distance d3 from 11 to the first fulcrum member 7 and the distance d4 from the first fulcrum member 7 to the support shaft 6 is appropriately set, the ratio is proportional to the rotation angle of the control lever 5. Thus, the support shaft 6 always moves to the right.
[0015]
Therefore, in the regulator of the double tilt type swash plate type hydraulic pump, the control lever moves in both the left and right directions as shown in the figure. Can always be moved in one direction to correct the change of the swash plate, and good swash plate tilt angle correction can be performed.
[0016]
【Example】
Hereinafter, examples of the present invention will be described.
[0017]
FIG. 1 is a sectional view of a hydraulic pump regulator (hereinafter, simply referred to as a “regulator”) employing a one-way drive link mechanism according to an embodiment of the present invention, as viewed from the front, and FIG. It is sectional drawing seen.
[0018]
The regulator 20 is mounted on a double tilt type swash plate type hydraulic pump (not shown), and includes a casing 21, a feedback sleeve 22 disposed in the casing 21, and a feedback sleeve 22. A spool 23, a control lever 24 (arm member) connected to the feedback sleeve 22, and a first fulcrum member 25 and a second fulcrum member 26 that constitute fulcrums when the control lever 24 swings as described later. have. Further, in the present embodiment, a coil spring 27 (elastic member) is provided which constantly urges the feedback sleeve 22 leftward within the casing 21.
[0019]
The feedback sleeve 22 and the spool 23 drive a servo cylinder (not shown) for changing the swash plate tilt angle of the hydraulic pump, and a relative positional relationship between the feedback sleeve 22 and the spool 23 is provided. Thus, the required hydraulic pressure is guided to the servo cylinder, and the servo cylinder is driven by the hydraulic pressure. The illustration of the hydraulic piping between the feedback sleeve 22 and the servo cylinder is omitted.
[0020]
The present embodiment is characterized in that a control lever 24, a support shaft 28 for indicating the control lever 24, and first and second fulcrum members 25 and 26 are used to drive a one-way drive link mechanism (hereinafter simply referred to as a "link mechanism"). According to this, even if the control lever 24 swings in either direction of the arrow 30 or 31, the feedback sleeve 22 is moved to the right in accordance with the swing of the control lever 24 in the direction of the arrow 30 or the arrow 31. In that it is configured to be slidable. Hereinafter, this will be described in detail with reference to FIGS.
[0021]
First, the casing 21 can be made of, for example, a casting. A link mechanism housing 32 and a sleeve housing 33 are provided inside the casing 21. These are constituted by a housing space formed in the casing 21 as shown in the figure, and communicate with each other. The link mechanism accommodating portion 32 is a space for disposing a link mechanism 29 described later in detail, and allows the control lever 24 to swing freely.
[0022]
The sleeve accommodating portion 33 is a space for disposing the feedback sleeve 22, and the feedback sleeve 22 is slidable in the left-right direction in the figure. The inner peripheral surface of the sleeve accommodating portion 33 is formed in a cylindrical shape, and a step portion 34 is formed in a part thereof. The step 34 serves as a seat for the coil spring 27.
[0023]
The casing 21 is provided with a plug member 35 as shown in the figure. The plug member 35 serves as a lid of the sleeve accommodating portion 33, and is formed in a bolt shape. The plug member 35 is screwed into the sleeve accommodating portion 33 from the left side of the casing 21 in the state in which the feedback sleeve 22 is accommodated.
[0024]
The feedback sleeve 22 is formed in a cylindrical shape as shown in the figure. The left end of the feedback sleeve 22 is enlarged in diameter, and a flange 36 is formed as shown in the figure. The coil spring 27 is arranged between the flange 36 and the step 34. By disposing the coil spring 27 at such a position, a predetermined flexure is generated, and the feedback sleeve 22 is urged to the left side in the figure by the elastic force caused by the flexure.
[0025]
The feedback sleeve 22 is provided with a plurality of ports 37, and these ports communicate with hydraulic piping between the feedback sleeve 22 and the servo cylinder.
[0026]
The spool 23 is exactly accommodated in the feedback sleeve 22 and is slidable in the feedback sleeve 22 in the axial direction (the left-right direction in the drawing). The spool 23 has a plurality of lands 38 formed thereon. The outer peripheral surface of the land 38 slides on the inner peripheral surface of the feedback sleeve 22.
[0027]
The link mechanism 29 includes the control lever 24, the support shaft 28, the first fulcrum member 25, and the second fulcrum member 26, as described above.
[0028]
The support shaft 28 is formed in a pin shape as shown in FIG. One end of the support shaft 28 is connected to the feedback sleeve 22, and the other end is fixed to the control lever 24.
[0029]
The control lever 24 is formed of a flat member, and has a base 38 and a swing arm 39. A through hole 40 is provided in the center of the base 38, and the support shaft 28 is fitted and fixed in the through hole 40. Above and below this through-hole 40, a circular cutout hole 41 (first engagement portion) and a cutout portion 42 (second engagement portion) are provided. These notches 41 and 42 penetrate the control lever 24 in the thickness direction. The functions of these notches 41 and 42 will be described later.
[0030]
On the other hand, the swing arm 39 is formed continuously below the base 38. The control lever 24 rotates as described later. In this case, the swing arm 39 swings in the directions of arrows 30 and 31 (see FIG. 1).
[0031]
The first fulcrum member 25 is formed in a stepped pin shape, and is screwed from the outside of the casing 21 as shown in the figure. The distal end portion 43 of the first fulcrum member 25 is formed with a small diameter, and this portion is inserted into the cutout hole 41 of the control lever 24.
[0032]
The second fulcrum member 26 is also formed in the shape of a stepped pin similarly to the first fulcrum member 25, and is screwed from the outside of the casing 21 as shown in the figure. The distal end portion 44 of the second fulcrum member 26 is formed to have a small diameter, and this portion is inserted into the cutout hole 42 of the control lever 24.
[0033]
The regulator 20 according to the present embodiment performs the following operation.
[0034]
First, when the control lever 24 is rotated about the support shaft 28 in the direction of the arrow 30, the inner peripheral surface of the cutout hole 42 abuts and engages with the second fulcrum member 26. In this state, the control lever 24 and the second fulcrum member 26 form a lever structure. When the control lever 24 is further rotated in the same direction, the second fulcrum member 26 forms a fulcrum, and the control lever 24 rotates in the direction of the arrow 30 with the second fulcrum member 26 as a fulcrum, and swings in the same direction. The moving arm 39 swings.
[0035]
Since the second fulcrum member 26 is located below the support shaft 28, the support shaft 28 moves rightward by the swing arm 39 swinging about the second fulcrum member 26 as a fulcrum as described above. That is, the feedback sleeve 22 slides to the right.
[0036]
On the other hand, when the control lever 24 is rotated about the support shaft 28 in the direction of the arrow 31, the inner peripheral surface of the cutout hole 41 abuts and engages with the first fulcrum member 25. In this state, a lever structure is configured by the raw fish lever 24 and the first fulcrum member. When the control lever 24 is further rotated in the same direction, the first fulcrum member 25 forms a fulcrum, and the control lever 24 rotates in the direction of arrow 31 with the first fulcrum member 25 as a fulcrum, and swings in the same direction. The moving arm 39 swings.
[0037]
Since the first fulcrum member 25 is located above the support shaft 28, the support shaft 28 moves to the right as the swing arm swings about the first fulcrum member 25 as a fulcrum as described above. That is, the feedback sleeve 22 slides to the left.
[0038]
In this way, the feedback sleeve 22 slides to the right regardless of whether the control lever 24 is rotated in the left or right direction. Therefore, when the regulator 20 is used in a double tilt type swash plate type hydraulic pump, a change in the tilt angle of the swash plate is corrected regardless of whether the tilt angle of the swash plate is set to the positive side or the negative side. Therefore, the feedback sleeve 22 can always be moved in one direction. As a result, good swash plate tilt angle correction can be performed.
[0039]
Particularly, in this embodiment, the feedback sleeve 22 is always elastically urged to the left by disposing the coil spring 27. That is, the support shaft 28 is elastically urged so that the first fulcrum member 25 and the second fulcrum member 26 always contact the control lever 24. Therefore, there is an advantage that the support shaft 28 and the control lever 24 can always be stabilized.
[0040]
In this embodiment, a so-called double lever structure is formed by the control lever 24 and the first fulcrum member 25 or the second fulcrum member 26. Therefore, the feedback sleeve 22 is slid rightward regardless of the rotation direction of the control lever 24. However, when the control lever 24 rotates in the direction of the arrow 30 or the arrow 31, the position of the fulcrum of the lever changes.
[0041]
Therefore, in order to always slide the feedback sleeve 22 at a constant rate regardless of the direction in which the control lever 24 rotates, as described with reference to FIG. 3, from the tip of the control lever 24 to the second fulcrum member 26. And the ratio of the distance from the second fulcrum member 26 to the support shaft 28, the distance from the tip of the control lever 24 to the first fulcrum member 25, and the distance from the first fulcrum member 25 to the support shaft 28. Must be set to an appropriate value, but this value can be set as appropriate for optimal design.
[0042]
In addition, in the present embodiment, the notch holes 41 and 42 are formed by circular through holes, but these form a contact portion with the first fulcrum member 25 and the second fulcrum member 26, and The first fulcrum member 25 and the second fulcrum member 26 are provided so as not to interfere with the control lever 24 when the control lever 24 rotates. Therefore, the cutout holes 41 and 42 can be formed in other shapes as long as such conditions are satisfied. For example, in addition to the circular shape, it can be formed in a notch groove or the like having one end opened. However, in order to reliably hold the control lever 24 by the elastic force of the coil spring 27, the shape of the contact portion between the notch holes 41 and 42 with the first fulcrum member 25 and the second fulcrum member 26 must be curved. It is desirable that
[0043]
【The invention's effect】
As described above, according to the present invention, the so-called double lever structure is constituted by the first fulcrum member, the second fulcrum member, and the arm member by the one-way drive link mechanism. By appropriately setting the position of the support shaft, the support shaft can be moved in a predetermined direction regardless of the moving direction of the arm member. As a result, for example, when this mechanism is used in a regulator of a double tilt type swash plate type hydraulic pump, even if the tilt angle of the swash plate is set to the positive side or the negative side, the change of the tilt angle of the swash plate is changed. Can be satisfactorily corrected.
[Brief description of the drawings]
FIG. 1 is a front sectional view of a hydraulic pump regulator employing a one-way drive link mechanism according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a hydraulic pump regulator employing a one-way drive link mechanism according to one embodiment of the present invention as viewed from a right side surface.
FIG. 3 is a view showing the operation principle of the one-way drive link mechanism of the present invention.
[Explanation of symbols]
Reference Signs List 20 Regulator 21 Casing 22 Feedback sleeve 23 Spool 24 Control lever 25 First fulcrum member 26 Second fulcrum member 27 Coil spring 28 Support shaft 29 Link mechanism 38 Base 39 Swing arm 40 Through hole 41 Notch hole 42 Notch hole

Claims (3)

A first fulcrum member and a second fulcrum member fixedly arranged at a predetermined interval, and are rotatably supported by a support shaft arranged between the first fulcrum member and the second fulcrum member. a first engaging portion engageable with the first pivot member by rotating the center and have a arm member and the second engaging portion is formed to engage with the second fulcrum member Yes,
When the arm member rotates about the support shaft and the first engagement portion engages with the first fulcrum member, the arm member rotates about the first fulcrum member as a fulcrum, and the arm member Is configured to rotate about the support shaft and the arm member to rotate about the second fulcrum member when the second engagement portion engages with the second fulcrum member. A one-way drive link mechanism. The one-way drive link mechanism according to claim 1,
A one-way drive link mechanism, further comprising an urging member for elastically urging the support shaft in a direction in which the first fulcrum member and the second fulcrum member abut on the arm member. The one-way drive link mechanism according to claim 1,
The first and second engagement portions are formed in a hole shape,
The one-way drive link mechanism, wherein the first fulcrum member is loosely inserted into the first engagement portion, and the second fulcrum member is loosely inserted into the second engagement portion.

Images