JPS6154931B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a throttle lever for opening and closing a throttle valve, and a throttle lever for reducing the opening degree of the throttle valve in conjunction with a control motor that operates in accordance with a control input signal. A shock absorber is installed in the regulating force transmission section between the throttle drive lever that regulates the swing limit to reduce the impact force between the throttle lever and the throttle drive lever. The present invention also relates to a throttle valve opening/closing device for a carburetor which prevents malfunction of its related mechanisms.

Conventionally, there has been a throttle lever for opening and closing the throttle valve, and a throttle drive that regulates the swing limit of the throttle lever in the direction of decreasing the opening of the throttle valve in conjunction with a control motor that operates in accordance with a control input signal. In a vaporizer equipped with a lever,
When the abutting portion on the throttle lever side and the abutting portion on the throttle drive lever side collide with each other, there is a risk that the control engine and related mechanisms may malfunction due to the impact vibrations generated.

In addition, due to frequent collisions between the abutment part on the throttle lever side and the abutment part on the throttle drive lever side, the abutment part tends to wear out, making it difficult to control the opening of the throttle valve. Maintaining high accuracy was not easy.

In view of these circumstances, the main object of the present invention is to eliminate the impact between the abutment part on the throttle lever side and the abutment part on the throttle drive lever side, thereby preventing malfunctions of the control engine and related mechanisms. A throttle for a carburetor that can prevent this, reduce wear on the contact part between the throttle lever and the throttle drive lever as much as possible, and maintain high accuracy in controlling the opening of the throttle valve. The purpose is to obtain a valve opening/closing device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A carburetor to which an embodiment of the present invention is applied will be described in detail below with reference to the drawings.

First of all, in FIGS. 1 to 3, a fuel nozzle 3 is disposed in the center of a ventilate part 2 formed in an intake path A of a carburetor 1, and a tire yoke is provided upstream of this fuel nozzle 3. A valve 4 is supported by a choke valve shaft 5, and a throttle valve 6 is supported by a throttle valve shaft 7 downstream of the fuel nozzle 3. A secondary intake passage B is formed in a position adjacent to the intake passage A, and the secondary throttle valve in this secondary intake passage B is opened and closed by a secondary throttle valve switch 8 to open and close the engine. The engine is configured to be able to replenish secondary air-fuel mixture into the combustion chamber of the engine in the high-speed rotation region of the engine, thereby increasing cylinder filling efficiency. Such a secondary air-fuel mixture replenishment device consisting of the secondary intake passage B, the secondary throttle valve switch 8, etc. has been well known in the past, and is not directly related to the present invention, so it will not be described in further detail. don't touch it.

The check valve shaft 5 is eccentric from the center of the check valve 4, so that when the check valve 4 is closed, the engine's suction negative pressure acts on the check valve 4 as an opening torque. The chiyoke valve shaft 5 extends from the inside of the intake passage A to the outside, and the part of the chiyoke valve shaft 5 extending outward from the intake passage A has one end facing the outer wall of the intake passage A. By being locked to the face part and the other end being locked to the chiyoke valve shaft 5, bias rotational force is applied to the chiyoke valve shaft 5 so as to always open the chiyoke valve 4 toward the maximum opening position. the return spring 9, and the first
A driven arm 13 that integrally has a driven arm 11 equipped with a following roller 12 that follows the cam surface of the cam plate 59, and is equipped with a following roller 14 that follows the cam surface of a second cam plate 60 (described later) at the tip end thereof. is also integrally supported on the chiyoke valve shaft 5 so as to be relatively rotatable, thereby transmitting rotational force to the chiyoke lever 17 (described later) via a pawl 20 protruding from the outer circumference. One end side of the plate 10 and an interlocking link 16 that moves forward and backward in conjunction with the rocking motion of a throttle lever (to be described later) are pivotally supported, and are fixed to the York valve shaft 5, so that the link 16 is integrally connected to the York valve shaft 5. A rotating plate 15 that rotates, a claw 19 that comes into contact with the claw 20 of the rocking plate 10, and a Chi-Yoke lever 17 that is fixed on the Chi-Yoke valve shaft 5, and one end of which is locked to the claw 20. At the same time, the other end side is the chiyoke lever 17.
A biasing spring 18 is locked to the biasing spring 18 and always applies an elastic force in the direction in which the claws 20 and 19 are in contact with each other.
and are provided.

Further, the throttle valve shaft 7 also extends from inside the intake passage A to the outside, and the part of the throttle valve shaft 7 extending outward from the intake passage A has one end facing the outer wall of the intake passage A. Since it is locked to the surface part and the other end side is locked to a gear 22 (described later), it is always biased counterclockwise around the throttle valve shaft 7 with respect to the gear 22 in FIGS. 3 and 4. A return spring 21 that applies rotational force is supported on the throttle valve shaft 7 so as to be rotatable relative to the throttle valve shaft 7, and the intermediate portion is pivotally supported by a pivot shaft 23 described later. and a gear 22 that meshes with a sector gear 25 formed on the base end side of a driven arm 24, which has a follower roller 26 at its tip that follows the cam surface of a third cam plate 61 (described later), and a throttle valve. The spacing plate 2 is rotatably supported on the throttle valve shaft 7 so as to be rotatable relative to the shaft 7, and the spacing plate 2 is pivotally supported on the throttle valve shaft 7 so as to be rotatable relative to the shaft 7.
The throttle drive lever 28 has a throttle drive lever 28 fixed to the gear 22 side via the throttle wire 7, and a locking part 40 locking one end of the throttle wire 42, as shown in detail in FIG. It also has a guide groove 41 for guiding the throttle wire 42, as shown in FIG.
When a tensile force is applied to the throttle wire 42, the throttle valve shaft 7 is rotated clockwise in FIG. 3 or 4 in a direction that increases the opening degree of the throttle valve 6 against the spring force of a return spring (not shown). The interlocking link 1 is fixed on the throttle valve shaft 7 so as to
A throttle lever 38 whose end opposite to the rotary plate 15 of No. 6 is pivotally supported is provided.

In FIGS. 1, 3, and 4, the throttle drive lever 28 swings around the throttle valve shaft 7 in conjunction with a control motor 46, which will be described later, which operates in accordance with a control input signal. The rocking limit of the throttle lever 38 in the direction of decreasing the opening degree of the throttle valve 6 is restricted. Throttle lever 38
The regulating force transmitting portion between the throttle lever 38 and the throttle drive lever 28 includes a throttle lever 38 and a throttle drive lever supported on at least one side of the throttle drive lever, for example, the throttle drive lever 28 side as shown in the figure. , a buffer device C is interposed to relieve the impact force between the throttle lever 38 and the throttle drive lever 28.

In the shock absorber C, an adjusting screw 31 having a male thread on the base end is loosely fitted into a loosely fitting hole bored in a bent portion 29 formed at the tip of the throttle drive lever 28. An adjustment nut 30 is screwed into the male threaded portion of the adjustment screw 31 that protrudes outward from the bent portion 29, and a tool such as a screwdriver is engaged with the proximal end surface of the adjustment screw 31. An adjustment groove 32 is formed for this purpose. The tip of the adjustment screw 31 protrudes toward the abutment portion 39 on the throttle lever 38 side, and the tip of the adjustment screw 31 has a cylindrical abutment 34 having an umbrella portion 35 at the tip. is slidably fitted in the axial direction of the adjustment screw 31. The body of the abutting element 34 includes
Abutment elements 34 are provided at diametrically opposed positions, respectively.
Elongated holes 36, 36' are bored in the axial direction of the adjusting screw 31, and a portion near the tip of the adjusting screw 31 is provided with a long hole 36, 36'.
A pin 33 that penetrates and projects in the diametrical direction is fixed, and the protruding portions at both ends of this pin 33 are connected to the abutment element 34.
is engaged with each elongated hole 36, 36'. and,
A resilient spring 37 is interposed between the umbrella portion 35 and the bent portion 29 of the abutting element 34, and this resilient spring 37
Due to this action, the abutment element 34 is always pushed toward the tip side of the adjustment screw 31.

In FIGS. 1 and 2, on the outer wall of each of the intake passages A and B of the carburetor 1, there is provided an external transmission part that supports a control motor 46 constituted by, for example, a pulse motor, via support arms 43 and 44. A frame 45 is supported. The inside of the control engine 46 and the transmission part outer frame 45
The transmission chamber D surrounded by
The gear shafts 56, 57 of the gears 53, 54, 55 of the reduction gear train 50 are rotatably supported by bearings formed in the common partition wall 47. That is, the output shaft 48 of the control motor 46 is
It projects into the transmission chamber D while being supported by a bearing 49 supported by a common partition wall 47.
A gear 52 fixed to the tip of the output shaft 48 protruding into the transmission chamber D has one end connected to the common partition wall 47.
A gear shaft 5 supported by a bearing portion formed therein.
It meshes with a gear 53 fixed on 6. And another gear 54 fixed on the gear shaft 56
meshes with a gear 55 fixed on a gear shaft 57 whose one end side is rotatably supported by a bearing formed in the common partition wall 47.

The control motor 46 is, for example, a pulse motor, and the engine temperature detected through the engine water temperature, etc.
The engine rotates in response to the application of forward rotation pulses or reverse rotation pulses, which are output signals from an electronic control circuit (not shown) that operates based on input factors such as the engine rotational speed and the temperature of the intake air of the engine. The output torque is transmitted through the reduction gear train 50 to the input side of the electromagnetic clutch 51 in the transmission shell 45 .

As shown in Figures 1, 2 and 5,
The drive shaft 58, which is the output shaft of the electromagnetic clutch 51, is
The drive shaft 58 is provided with a displacement detection plate 62, a collar 63, a third cam plate 61, and a collar 64 for detecting the amount of rotational displacement. , the second cam plate 60, the collar 65, and the first cam plate 59 are fitted using their fitting holes. At this time, a flat portion 58a is formed in a diametrically opposing portion of the drive shaft 58 over the entire length of the protruding portion of the drive shaft 58, and a displacement detection plate 62 and a third cam plate 6 are provided.
1. The fitting holes of the second cam plate 60 and the first cam plate 59 are shaped to match the cross-sectional shape of the drive shaft 58. Since the drive shaft 58 has such a flat portion 58a, the rotational torque of the drive shaft 58 can be effectively transmitted to the displacement detection plate 62 and each of the cam plates 59, 60, 61.

Further, a pair of pin insertion holes 66, 66' are formed in the displacement detection plate 62, sandwiching the fitting hole, and a pair of pin insertion holes 67, 67' are formed in the collar 63 at positions facing each other in the diametrical direction. The third cam plate 61 has a pair of pin insertion holes 68, 68' sandwiching the fitting hole.
A pair of pin insertion holes 69 and 69' are formed in the collar 64 at diametrically opposed positions, and a pair of pin insertion holes 70 and 70' are formed in the second cam plate 60 with the fitting holes in between. is formed, and the collar 65 has a pair of pin insertion holes 7 at diametrically opposed positions.
1 and 71' are formed in the first cam plate 59, and a pair of pin insertion holes 72 and 72' are formed in the first cam plate 59, sandwiching the fitting hole.
8, 69, 70, 71 and 72 have insertion pins 73
are inserted through each pin insertion hole 66',
Insertion pins 73' are inserted through 67', 68', 69', 70', 71' and 72'. These pair of insertion pins 73, 73' are connected to each cam plate 59, 6.
0, 61 and the displacement detection plate 62, and constitutes a phase shift prevention means for performing cam control and displacement detection with high accuracy. As the phase shift prevention means, instead of using the insertion pins 73, 73' as shown, each cam plate 5
9, 60, 61 and the displacement detection plate 62 may be fixed by caulking so as not to cause a relative phase shift. A male thread is formed at the tip of the drive shaft 58, and each cam plate 59, 60, 61 is tightened by screwing a tightening nut 74 onto this male thread.
The displacement detection plate 62 is securely mounted on the drive shaft 58.

As shown in FIGS. 1 to 3, the first cam plate 59 is located at an axial position corresponding to the following roller 12 of the driven arm 11, and the second cam plate 60 is located at the position corresponding to the following roller 12 of the driven arm 11.
The third cam plate 61 is located at an axial position corresponding to the following roller 14 of No. 3, and the third cam plate 61 is located at an axial position corresponding to the following roller 26 of the driven arm 24.

In FIGS. 1 to 3 and 6, a female threaded portion 77 formed on the transmission part outer frame 45 has a male threaded portion formed on the proximal end side of the rotating shaft 75 parallel to the throttle valve shaft 7. 76 is screwed together, and an adjustment groove 78 is formed on the base end surface of the rotary shaft 75, in which a tool such as a screwdriver can be engaged, and an adjustment groove 78 is formed on the distal end surface of the rotary shaft 75. , driven arm 2
The pivot shaft 23 that pivots the rotation shaft 75 is parallel to the rotation shaft 75, and the center axis of the pivot shaft 23 is eccentric from the center axis of the rotation shaft 75 by a distance Δ. ing.

A cylindrical member 79 is rotatably fitted onto the pivot shaft 23, and an intermediate portion of the driven arm 24 is fixed to the cylindrical member 79. Followed arm 24
The sector gear 2 is always operated by the action of a bias spring 81 whose one end is locked to an end plate 80 fixed to the tip of the pivot shaft 23 and whose other end is locked to the driven arm 24.
For example, in FIG. 3, a biasing force is applied in the clockwise direction so that the meshing force between the gear 5 and the gear 22 is biased in one direction. That is, the biasing spring 81
constitutes a backlash direction maintaining mechanism for eliminating uneven meshing between the sector gear 25 and the gear 22.

Also, by engaging the tool in the adjustment groove 78, the rotation shaft 7
5, the pivot shaft 23 is swung around the central axis of the rotation shaft 75, and as a result, the amount of backlash in the meshing between the sector gear 25 and the gear 22 is changed. Using sector gear 2
5 and the gear 22 can be adjusted. That is, the eccentric shaft structure formed by the rotation shaft 75 and the pivot shaft 23 constitutes a backlash adjustment mechanism.

Next, the operation of the illustrated vaporizer 1 will be explained. First, at the time of first idle, that is, at the time of starting, the control prime mover 46 constituted by, for example, a pulse motor is driven in normal rotation, so that the rotational torque of the control prime mover 46 is transmitted through the reduction gear train 50 and the electromagnetic clutch 51. Drive shaft 58
3, and the drive shaft 58 is rotated counterclockwise in FIG.

As the drive shaft 58 rotates, the first cam plate 59,
The second cam plate 60, the third cam plate 61, and the displacement detection plate 62 rotate integrally with the drive shaft 58, but at this time, the first cam plate 59 and the second cam plate 60 are out of phase in the rotation direction. Because they are arranged out of alignment, the first
The cam surface of the cam plate 59 contacts the follower roller 12 and swings the rocking plate 10 clockwise in FIG. 14 and further swings the swing plate 10 clockwise in FIG. 3 via the driven arm 13. As a result, the pawl 20, the biasing spring 1
8. The chiyoke valve shaft 5 is rotated clockwise in FIG. 3 against the elastic force of the return spring 9 via the pawl 19 and the chiyoke lever 17, so that the chiyoke valve 4 is rotated to the closed position. be done.

During this time, the cam surface of the third cam plate 61 is constantly in contact with the follower roller 26, causing the driven arm 24 to swing counterclockwise in FIG. 3 around the pivot shaft 23. Along with this, the sector gear 25 causes the gear 22 to rotate clockwise in FIGS. 3 and 4 around the throttle valve shaft 7 against the spring force of the return spring 21, and as the gear 22 rotates, The throttle drive lever 28 is swung clockwise in FIGS. 3 and 4 around the throttle valve shaft 7 integrally with the gear 22. And throttle drive lever 2
8 presses the contact portion 39 of the throttle lever 38 via the shock absorber C.
The throttle lever 38 is swung clockwise in FIGS. 3 and 4 about the throttle valve shaft 7 against the spring force of a return spring (not shown). As a result, the throttle valve shaft 7 rotates clockwise in FIGS. 3 and 4 together with the throttle lever 38, thereby opening the throttle valve 6 to the fast idle opening position.

After the engine is started, the suction negative pressure acts as an opening torque on the yoke valve 4, and if this opening torque increases beyond the set torsional load of the spring 18, the yoke valve 4 acts on the torsional force of the spring 18 and the opening torque. It opens until the torque is balanced and prevents the air-fuel mixture created in the intake passage A from becoming too rich. After the engine starts, when the temperature of the engine rises and exceeds the set temperature, the control engine 46 is driven in the reverse direction, and the drive shaft 58 is driven in the clockwise direction in FIG. rotated in the direction The first cam plate 59, the second cam plate 60, the third cam plate 61, and the displacement detection plate 62 are all attached to the drive shaft 58.
At this time, due to the spring force of the return spring 9, the rocking plate 10 rotates clockwise in FIG. 3, the follower roller 14 first separates from the cam surface of the second cam plate 60, and the follower roller 12 moves along the cam surface of the first cam plate 59. In conjunction with this, the chiyoke valve shaft 5 rotates counterclockwise in FIG. 3, so that the opening degree of the chiyoke valve 4 increases.

During this time, the follower roller 26 moves along the cam surface of the third cam plate 61, and the follower arm 24 moves along the pivot shaft 2.
3 in a clockwise direction in FIG.
Accordingly, the fan gear 25 rotates the gear 22 receiving the spring force of the return spring 21 counterclockwise around the throttle valve shaft 7 in the counterclockwise direction in FIGS. 3 and 4, so that the throttle drive lever 2
8 swings in the counterclockwise direction in FIGS. 3 and 4 around the throttle valve shaft 7 integrally with the gear 22. As a result, the throttle lever 38 swings counterclockwise in FIGS. 3 and 4 due to the spring force of a return spring (not shown), and the throttle valve shaft 7 accordingly swings in the counterclockwise direction as shown in FIGS. 3 and 4. By rotating counterclockwise in FIG. 4, the throttle valve 6 is closed to the normal idle opening position.

During idle control when an auxiliary machine such as a car cooler compressor is connected to the engine as a load, the control motor 46 is further driven in the reverse direction, thereby causing the drive shaft 58 to further rotate clockwise in FIG. 3. As the third cam plate 61 further rotates clockwise in FIG. 3, the driven arm 24 swings counterclockwise in FIG. 3 around the pivot shaft 23. As a result, the throttle valve shaft 7 is rotated clockwise in FIGS. 3 and 4 via the gear 22, the throttle drive lever 28, the shock absorber C, and the throttle lever 38, and the throttle valve 6 is rotated in the direction of increasing opening. is rotated.

During autocruise, that is, when driving at a constant speed, the carburetor 1 basically operates in the same manner as during idle control, but at this time, the opening degree of the throttle valve 6 is greater than the opening degree during idle control. It is set to be large.

During normal operation, the throttle lever 38 is swung around the throttle valve shaft 7 via the throttle wire 42 in accordance with the driver's operation, and the opening degree of the throttle valve 6 is accordingly adjusted according to the driver's will. adjusted based on At this time, the shock absorber C functions as a stopper for the contact portion 39, and the throttle drive lever 28 restricts the swing limit of the throttle lever 38 in the direction of decreasing the opening degree of the throttle valve 6. Further, the swinging of the throttle lever 38 in the direction of increasing the opening degree of the throttle valve 6 causes the rotating plate 15 to rotate counterclockwise in FIG. As a result, the opening degree of the choke valve 4 is increased so that the intake air amount does not become too small.

As described above, according to the present invention, the regulating force transmission section between the throttle lever and the throttle drive lever includes a throttle that is supported by at least one side of the throttle lever and the throttle drive lever. A shock absorber is installed to reduce the impact force between the throttle lever and the throttle drive lever, so the contact area between the throttle lever side and the throttle drive lever side is reduced. It is possible to eliminate shock and prevent malfunction of the control engine and its related mechanisms, and it is also possible to reduce wear on the contact part between the throttle lever and throttle drive lever as much as possible, resulting in high The opening of the throttle valve can be controlled with precision.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional front view of essential parts of a carburetor to which an embodiment of the present invention is applied, FIG. 2 is a plan view of the carburetor shown in FIG. 1, and FIG. 3 is a partial front view of the carburetor shown in FIG. A partial cross-sectional side view of the main part, FIG. 4 is an enlarged partial cross-sectional view of the main part of FIG.
FIG. 5 is an exploded perspective view of the cam portion shown in FIG. 1, and FIG. 6 is an enlarged view of the main part of FIG. 1 in partial cross section. 6... Throttle valve, 7... Throttle valve shaft,
28... Throttle drive lever, 38... Throttle lever, 42... Throttle wire, 4
6...Control motor, C...Buffer device.

Claims (1)

[Claims] 1 Throttle valve shaft 7 supporting the throttle valve 6
A throttle lever 38 is fixed to the throttle lever 38 and swings via a throttle wire 42 to rotate the throttle valve shaft 7 to open and close the throttle valve 6; The throttle lever 38 opens the throttle valve 6 by swinging in conjunction with a control engine 46 that is pivotably supported to swing relative to the lever 38 and operates in accordance with a control input signal. In the throttle valve opening/closing device for a carburetor, which is equipped with a throttle drive lever 28 that regulates the limit of rocking in the direction of decreasing the throttle angle, a regulating force transmission portion between the throttle lever 38 and the throttle drive lever 28 is , a shock absorbing device for alleviating the impact force between the throttle lever 38 and the throttle drive lever 28 while being supported on at least one side of the throttle lever 38 and the throttle drive lever 28; A throttle valve opening/closing device for a carburetor in which C is installed.