JPH0266382A - Solenoid actuator - Google Patents

Abstract

PURPOSE:To enable a position control to be attained of three or more points by an on-off operating solenoid by connecting a plunger to a link, having a rotary axis orthogonal with a moving straight line of this plunger, by a connecting rod and providing a spring means urging the link in a predetermined direction. CONSTITUTION:A reciprocation movable plunger 3 is provided in a solenoid main unit 2 and connected by a connecting rod 7 to a turn arm 4a in a plunger side of a link 4 of reverse T-shape having a rotary axis 4A orthogonal with the plunger 3 on its moving straight line. While a tension coil spring 8 is mounted to a turn arm 4b in an opposite side to the turn arm 4a of the link 4, urging it against attractive force of a solenoid 1, and a driven object is connected to a turning end in a top side part 6 of the link 4. Accordingly, a stroke of the plunger 3 is sufficiently ensured, eliminating an influence by sliding resistance, and a position control can be attained of three or more points by using an ordinary on-off operating solenoid.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solenoid actuator, and particularly to a solenoid actuator suitable for driving choke valves, governors, etc. of general-purpose engines.

[Conventional technology]

Conventionally, it has been relatively common to use solenoids to control the position of two arbitrary points. An example of "on" and "off" control of the switch lever using this solenoid is shown in FIG.

In FIG. 8, when electric power is applied to the solenoid 51, the plunger 52 moves in the direction of the arrow X in the figure against the home position return spring (hereinafter referred to as spring) 53 due to the suction force Fso of the solenoid ( (See the solid line in the same figure).

As a result, the switch lever 61 is set to the position shown by the solid line in the figure.

At this time, the switch is "ON".

On the other hand, when the application of power to the solenoid 51 is stopped, the repulsive force FSP of the spring 53 causes the plunger 52 to move in the X' direction in the figure and return to the position shown by the two-dot chain line. As a result, the switch lever 61 is set to the position indicated by the two-dot chain line in the figure. At this time, the switch is “off” (
OFF) J. The suction force F of the solenoid 51 in this case. The characteristics are shown in FIG. 9 together with the repulsive force Fsp of the spring 53.

In FIG. 9, the X-axis indicates the moving distance of the plunger 52, with the origin being the position when the suction force of the solenoid 51 reaches its maximum value. Most commercially available solenoids have this type of suction force characteristic.

In addition, the attraction characteristics can be changed depending on the shape of the core, etc.
There is also a device that has the power proportional attraction characteristic shown in FIG. 11, is balanced with a linear spring, and can be controlled at an intermediate position by adjusting the applied power.

FIG. 11 shows the attraction force characteristics of the solenoid 71 used in the electromagnetic proportional control valve 70 shown in FIG.
This is shown along with the repulsive force of .

[Problem to be solved by the invention]

However, using a solenoid having the suction force characteristics shown in FIG. 9 of the above-mentioned conventional example, it is difficult to perform intermediate position control in balance with a linear spring, similar to the solenoid having the suction force characteristics shown in FIG. 11. There are the following problems. That is, as shown in FIG. 12, the suction force F of the solenoid. When using a large range of attraction force F, change the slope of the spring repulsion force FSP to match the attraction force characteristics. Therefore, it is necessary to use a spring with a large spring constant, which results in a disadvantage that the usable stroke ΔX becomes small.

■As shown in Fig. 13, the suction force F of the solenoid. When using a part with a gentle slope, the characteristics will be close to those shown in Fig. 11 (this makes control easier and the stroke can be set sufficiently large, but the suction force F of the solenoid is smaller than in case ① above). Since the area is used, only a small driving force can be obtained with respect to the supplied power, and there are disadvantages in that the influence of sliding resistance of the plunger etc. is large and accuracy is reduced.

On the other hand, the conventional solenoid having the suction force characteristics shown in FIG. 11 is a custom-made product and is expensive.

[Purpose of the invention]

The present invention has been made in view of the problems of the conventional example, and its purpose is to provide a solenoid actuator that can control the position of three or more points using a commercially available and inexpensive solenoid for on/off operation. Our goal is to provide the following.

[Means to solve the problem]

In the present invention, a solenoid including a plunger capable of reciprocating in a predetermined direction, and a link having a rotation axis perpendicular to the moving straight line of the plunger are provided, and the plunger and the end of the link on the plunger side are provided. are connected by a connecting rod, and the link is equipped with a spring means for urging the link in a predetermined direction against the suction force of the solenoid.
This structure is intended to achieve the above-mentioned purpose.

[First Embodiment] Hereinafter, a first embodiment of the present invention will be described based on FIGS. 1 to 4.

The embodiment shown in FIG. 1 has a solenoid 1 that includes a solenoid body 2 and a plunger 3 that can reciprocate within the solenoid body 2 along its longitudinal direction. A link 4 made of an inverted T-shaped plate member having a rotating shaft 4A perpendicular to the straight line of movement of the plunger 3 substantially on the straight line of movement.
is installed.

To explain this in more detail, this link 4 has a top part 6 which is perpendicular to the bottom part 5 and located in the same plane as the bottom part 5 from the IIU 22 part 5 and a part of the bottom part 5 which is approximately the center of the bottom part 5. is formed from. A rotating shaft 4A is provided at the intersection of the center line of the bottom side 5 and the center line of the top side 6.
The link 4 can rotate around this rotating shaft 4A. The rotating end of the bottom portion 5 on the plunger 3 side and the plunger 3 are connected by a connecting rod 7. Here, the plunger 3 side of the rotation shaft 4A of the bottom portion 5 of the link 4 is referred to as a rotation arm 4a, and the opposite side is referred to as a rotation arm 4b.

Further, the other end of a tension coil spring (hereinafter referred to as a spring) 8, whose one end is locked to a fixed object, is locked to the rotating end on the opposite side of the bottom portion 5.

Therefore, the link 4 is urged counterclockwise in FIG. 1 by the spring 8 against the attraction force of the solenoid 1.

A driven object (not shown) whose position is to be controlled is connected to the rotating end of the top side 6 of the link 4.

The solenoid 1 is also provided with a power control circuit 9 that controls the power supplied from the power source 10 to the solenoid 1 .

Next, the principle of the position control operation of this embodiment will be explained based on FIGS. 2 and 3.

Let X be the moving distance of the plunger 3 in the direction of leaving the solenoid body 2 from the position when the suction force of the solenoid 1 is maximum, and the suction force of the solenoid 1 F. A spring 8 biases the link 4 counterclockwise in FIG.
Let y be the displacement in the tensile direction. As shown in Figure 1,
When X → (+) large, y → (+) large.

The length of the connecting rod 7 is 28. The length of the spring 8 is 12, the length of the rotating arm 4a is rl + the length of the rotating arm 4b is r2, it > rl , it ) rz, x,
If y is expressed by the rotation angle θ of the rotating arms 4a and 4b around the rotation axis 4A, then from FIG. 2, X=r((cos 1l
so cos (θ105o))・・・・・・(1
)y = r, (sin(θ±θsp) −5
in θsp l ・・・・・・(2) θso:X
"" The angle formed by the rotating arm 4a with the X direction at O (initial position).

θsp: Angle formed by the rotating arm 4b with the X direction at x=o becomes.

Tensile force of spring 8 F5. ' is the spring constant k, FSP = k (c' - y) = kc -ky - c-ky ...... (3)
(Here, C is the initial load, and C'' is the elongation from the natural length of the spring 8 when the initial load C is set.

Substituting equation (2) into equation (3), Fsr = c k −rz (sin(θ→−θ
sp) sin θ5. ．． )...(3)゛Next, the attraction force F of the solenoid is applied in the X direction by the link 4.
, o, and the force Fsr that balances them is determined.

In FIG. 3, rotating arms 4a, 4 about rotation axis 4A are shown.
Since the moments acting on b are equal, F r + =
F'rz・"-(4)
However, Fsp・cos (π/2−(θ10,.

))=F...
・(5) Also F3F' ・cos (θ+θ5r)=
F'...(6) Equation (5) 2 Equation (6) is transformed into Equation (
4) and rearranging, we get Fsr=Fsr' ・(r
z・cos (θ+θ8.)/rBsin(θ+θ,.

)) ...(7) becomes. Here, for convenience of explanation, θ3P→0. θ,. →0
, rl = r, = 1, the above equation becomes F , , =
(CO3θ/sinθ)・Fsp= (cosθ/s
inθ)・(c−ksinθ)・・・・・・(8)
becomes.

Here, an arbitrary balance point P-Q is set on the fourth line indicating the attraction force characteristics of the solenoid 1, FSP is calculated so as to pass through these points P and Q, and C and k are determined.

If the link is set so that θ=0 to 90° at x=0 to 1, then from equation (8), when x=0.7, Fsr=0.13 Balance point (
0) When x=0.2 F! +P=1.04 Balance point (P) c=1.38 k=1, and the illustrated curve FSF is obtained.

Here, a straight line FSF passing through (P) and (Q) is also written (same structure as the conventional example in Fig. 8).The characteristic curve approaches FSO near point P, making accurate position control impossible. I understand.

Next, in the above equations (1) and (2), θ,. →0.
θ, 2→0. If r+ = rz = 1, then x =
1-cos θ −−−−・−(1) 'y=s
inθ ・・・・・・(2)′, and when differentiated with respect to θ, d x / dθ=sin
θ −・・−(1) “dy/dθ= Cos θ
・−・・−・(2) ”.

In this case, d x / dθ- at θ-0(x!#O)
0, dy/dθ', 1 and d x / dθ<dy/
It becomes dθ.

Also, dx/dθζ1 at θ-90(x':xMAX)
, dy/do#o becomes d x / dθ) dy/dθ
becomes.

By using this relationship and adjusting each initial value according to the stroke and suction characteristics, it is possible to move y largely for a small displacement of X at X′, 0, and to make the movement of y small for a small displacement of X at can.

As explained above, according to the first embodiment, the suction force F of the solenoid 1. is large, a wide stroke of the plunger 3 can be secured within the range where the sliding resistance of the plunger 3 can be ignored, and the moving distance X of the plunger 3 is X-0
At , the displacement y in the tensile direction of the spring 8 is large (moves) against the suction force of the solenoid that biases the link 4 in response to a minute displacement of X, and at x = x MAX, y can be set so that it moves small, which solves the problems ① and ② of the conventional example mentioned above, and reduces the spring constant, initial load, and initial position of the link.

By appropriately setting the arm length etc. of the link, on/off
The off-operation solenoid has the advantage that intermediate position control of the driven object is possible.

[Second Embodiment] Next, a second embodiment of the present invention will be described based on FIGS. 5 to 7.

This second embodiment applies the present invention to a choke valve 32 installed in a carburetor 31 of a general-purpose engine 30 shown in FIG.
It was used for driving. In FIG. 7, reference numeral 33 indicates an air cleaner connected to the capretor 31.

A solenoid 4 for driving a choke valve 32 is mounted on one side wall of the carburetor 31, as shown in FIGS. 5 and 6.
0 is fixed in a state protruding outward.

The tip of the plunger 41 that forms the movable part of the solenoid 40 is connected to an operation link 35 provided at the upper end of the valve shirt 32a (FIG. 6) that forms the rotation axis of the choke valve 32.
It is connected to the right end of the body by a connecting rod 36. A spring 37 is interposed between the upper end of the operating link 35 in FIG. 5 and the other side wall 31b of the capretor 31. It is designed to be biased counterclockwise.

Specifically, the operation link 35 is made of a so-called cylindrical plate member, and is arranged so that the valve shirt 32a, which forms the axis of rotation thereof, is located substantially on the straight line of movement of the plunger 41.

The solenoid 40 is connected to a controller 42 for controlling the solenoid, which is connected to a power source (not shown). The controller 42 has a built-in suction temperature sensor, an operation time sensor, etc. (not shown), and is adapted to adjust the electric power supplied to the solenoid 40 as necessary.

According to the second embodiment configured as described above, when no power is supplied to the solenoid 40, the spring 37.
The operation link 35 is rotated counterclockwise in FIG. 5 by the action of a return spring (not shown) for the plunger 41 of the solenoid 40.

At this time, the choke valve 32 rotates integrally and enters a so-called fully open state.

When medium power is supplied to the solenoid 40, the attraction force Fso of the solenoid 40 causes the operation link 35 to
However, a force FOF in the direction of movement of the plunger and a suction force F of the solenoid are generated at the connecting point of the operation link 35 on the plunger side due to the tensile force of the spring 37. Rotate clockwise in Figure 5 until the two are balanced. At this time, the choke valve 32 rotates integrally and is set to an intermediate position, resulting in a medium opening state.

When large electric power is supplied to the solenoid 40, the suction force of the solenoid 40 increases to a suction force F. is link 3
5, the operating link 35 rotates further clockwise until the plunger 41 and the connecting rod 36 are substantially in a straight line. At this time, the choke valve 32 rotates integrally and enters a so-called fully open state.

As described above, the second embodiment has the advantage that it is possible to set a so-called half-choke state, which could not be achieved conventionally using only one solenoid for normal on/off control.

〔Effect of the invention〕

Since the present invention is configured and functions as described above, according to the present invention, the links and springs can be adjusted simply by setting the initial position of the link, the arm length of the link, the initial load applied to the link, the spring constant, etc. to the required values. By the action of the means, the driven object connected to the link can be controlled to a desired position, and even in the area where the solenoid's suction force is large, the plunger can have a sufficient stroke. It is possible to solve the problem of reduced accuracy due to the effects of sliding resistance, etc., and it is possible to control the position of three or more points using a solenoid for on/off operation, which is highly commercially available, inexpensive, and effective for high-mix, low-volume production. It is possible to provide an unprecedented solenoid actuator.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention, FIG. 2 is an explanatory diagram of the principle of position control in the embodiment of FIG. 1, and FIG. 3 is a suction force F of the solenoid shown in FIG. 2. A diagram for explaining the relationship between the force Fsp generated in the link and the tensile force F5.' in a state of balance between the spring tensile force Fsr' and the tensile force F5.'
Figure 4 shows the suction force F of the solenoid in Figure 2. FIG. 5 is a configuration diagram showing the second embodiment of the present invention, FIG. 6 is a bottom view of FIG. 5, and FIG.
The figure is an overall perspective view of a general-purpose engine equipped with the solenoid actuator of the embodiment shown in Figure 5, and Figure 8 is a conventional on/off engine.
An explanatory diagram showing an example of a switch lever drive part using a twist and fit for off operation, Fig. 9 is a diagram showing the attraction force characteristics of the solenoid in Fig. 8, and Fig. 10 is a diagram showing the conventional electromagnetic proportional attraction force characteristics. An explanatory diagram showing an example of an electromagnetic proportional control valve using a solenoid having a FIG. 3 is a diagram for explaining problems when controlling an intermediate position using a solenoid having special characteristics. 1... Solenoid, 3... Plunger, 4... Link, 4A... Rotating shaft, 7
. . . Connecting rod, 8 . . . Tension coil spring as spring means. Patent Applicant Suzuki Motor Co., Ltd. Figure 3 A1 Figure 4 θ 9o0(θ) Figure Figure 10

Claims (1)

[Claims] (1) A solenoid including a plunger capable of reciprocating in a predetermined direction, and a link having a rotation axis perpendicular to the moving line on the moving line of the plunger, and connecting the plunger and the link on the plunger side. The solenoid actuator is characterized in that the end portions are connected to each other by a connecting rod, and the link is equipped with a spring means for biasing the link in a predetermined direction against the attraction force of the solenoid.