JPS611574A - Safety mechanism in steering force change-over device - Google Patents

Abstract

PURPOSE:To make it possible to avoid shaking of a steering wheel which is disengaged from wheels at the position of a speed changing mechanism, by providing a cut-off valve for blocking the communication of an introduction passage upon an non-neutral operation in which an output shaft is not engaged with an engaging section for the output shaft. CONSTITUTION:An introduction passage 43 is connected to a diaphragm chamber 42 which is defined by a diaphragm 41 in a diaphragm actuator 40, which is attached to one end of a retractable rod 30, and is connected at its midway point with a selector valve 45 through a cut-off valve 44 having therein a valve chamber 46 in which a valve element 47 is fitted, slidably in a direction orthogonal to the axis of a rack shaft 3. The front end of the valve element 47 is engaged in a recess 49 formed in the outer periphery of the rack shaft 3 at the neutral position of the latter.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a steering force switching device that switches the steering force of a steering wheel by switching a transmission mechanism using gears.

<Prior art> In the steering gear of an automobile, in order to reduce the steering force of the steering wheel at low speeds and when stationary,
Transmission mechanisms using gears between the steering wheel and the steering gear are known, but when trying to maintain the correct position of the steering wheel, for example, in a transmission mechanism using a planetary gear mechanism, the sun gear, planetary gear, etc. It is conceivable to form a convex portion on one side and a concave portion on the other side so that the gear arm engages with the gear arm only at points on the circumference.

Furthermore, when switching the transmission mechanism using engine negative pressure, one end of the lever that connects the steering gear and steering wheel directly or switches to deceleration is connected to the diaphragm of the diaphragm actuator. It is conceivable that an introduction passage is connected to the diode flam chamber, and a switching valve is provided to turn on and off the negative pressure of the engine led to the introduction passage by operation of the driver.

<Problems to be Solved by the Invention> In such a device, when the transmission mechanism is in a deceleration state and the steering wheel is turned, when the driver operates the switching valve to change the transmission mechanism to increase speed, the lock of the ring gear is released. Ruka,
If the sun gear and the planetary gear arm only mesh at the circumferential points, the sun gear and the planetary gear arm will not connect, resulting in an underground condition. As a result, the handle and tire were previously connected, but were separated at the transmission mechanism, causing the handle to become flat and rotate up to 360 degrees to connect the sun gear and planetary gear arms. there were.

<Means for Solving the Problems> In order to solve the above-mentioned problems, the present invention forms an engaging portion on the output shaft, and when the output shaft engaged with the engaging portion is in the neutral state, the engine is not supplied from the switching valve. Negative pressure or atmospheric pressure is introduced to the diaphragm actuator (an introduction passage is communicated with the actuator), and a cutoff valve is provided that cuts off communication of the introduction passage when the output shaft that is not engaged with the engaging part is not in neutral. It is something to do.

<Operation> According to the present invention, with the above configuration, when the steering wheel is not in the neutral position, the cutoff valve shuts off the communication of the inlet passage, and when the steering wheel is in the neutral position, the inlet passage is opened and the negative pressure of the engine or the atmospheric pressure from the switching valve is removed. The gear is guided to the diaphragm actuator and the lever is activated to change the speed of the transmission mechanism.

<Example> Embodiments of the present invention will be described below based on the drawings.

FIG. 2 shows an example of an embodiment of the present invention, where ▪ is an input shaft on the steering wheel side, and 2 is a pinion shaft on the steering gear side. The steering gear is a rank pin-on type, and 3 indicates the rank axis. A pinion 4 that meshes with a rack 3a of a rank shaft 3 is formed on the pinion shaft 2, and a spline 10 is formed on the input shaft 1. 5 is a gear hook.

A sun gear 11 is spline-fitted to the spline 10 so as to be able to move only axially, and a planetary gear arm 6 is fixed to the pinion shaft 2. A planetary gear 7, which is always in mesh with the sun gear 11, is supported by a shaft 8 on the planetary gear arm 6. Further, a ring gear 9 is rotatably provided along the inner circumference of the gear box 5.
The planetary gear 7 is meshed with the planetary gear 7. A convex portion 12 is provided on the sun gear 11 side at the facing portion of the sun gear 11 and the planetary gear arm G.
However, a recess 13 that engages with the projection 12 is formed on the planetary gear arm 6 side, so that the projection 12 and the four parts 13 can be engaged and disengaged at one point on the circumference. The engagement and disengagement between the convex portion 12 and the concave portion 13 is performed by the sun gear 11 moving forward and backward on the input shaft 1 and approaching and separating from the planetary gear arm 6. The operating device for the sun gear 11 for performing this engagement and disengagement is the third
As shown in the figure, an annular groove 16 is provided in the sun gear 11,
A lever 1 that swings around a shaft 15 within a gear case 5
4, a pin J7 that engages with the annular groove 16 is protruded from one end of the lever 14, and a connecting rod 18 is connected to the other end.

The engagement/disengagement actuating device is provided with a locking mechanism that allows rotation of the ring gear 9 when the convex portion 12 and the concave portion 13 are engaged, and restricts rotation of the ring gear 9 when the engagement is released. There is. As shown in FIG. 4, the mechanism has a structure in which four portions 21 are provided at a plurality of locations on the outer peripheral surface of the ring gear 9, and an engaging convex portion 22 that engages with the recessed portion 21 is provided on the lever 14. Incidentally, reference numeral 20 denotes a spring that constantly presses the engagement convex portion 22 against the outer peripheral surface of the ring gear 9, and presses the lever 14 via the presser 19.

Next, the operating mechanism and safety mechanism of the lever 14 will be described.

As shown in FIG. 1, the connecting rod 18 is coaxially connected to a reciprocating rod 30, and this retracting rod 30 is connected to a housing 31.
It is rotatably supported on the shaft. A cylinder chamber 32 is formed in the housing 31, and a piston 3 is installed in this cylinder chamber 32.
3 is slidably guided in a direction perpendicular to the axis of the reciprocating rod 30. A piston rod 34 is integrally molded on the piston 33 at right angles to the axis of the forward/backward rod 30, and the tip of the piston rod 34 is engaged with an engagement groove 35 formed on the outer periphery of the forward/backward rod 30 at the retreating end of the forward/backward rod 30. It is designed to match. Inside the cylinder chamber 32 is a spring 3 that presses the piston 33 in a direction opposite to the advancing/retracting rod 30.
6 is inserted into the housing 31, and a piston rod 34 is inserted into the housing 31.
Suction boat 37 where the cylinder chamber 32 and the outside communicate with each other
is formed. The housing 31, the piston 33, the piston rod 34, and the spring 36 constitute a locking mechanism 38 for the reciprocating rod 30.

One end of the advance/retreat rond 30 is connected to a diaphragm 41 of a diaphragm actuator 40, and the diaphragm 4I
The diaphragm chamber 42 is divided by the introduction passage 4.
3 is connected, and this introduction passage 43 is connected to a switching valve 45 via a cutoff valve 44 in the middle. A valve body 47 is fitted into the valve chamber 46 of the shutoff valve 44 so as to be slidable in a direction perpendicular to the axis of the rack shaft 3, and the tip of the valve body 47 is located at the neutral position of the rack shaft 3 and is located at the outer periphery of the rank shaft 3. It is adapted to engage with a recess 49 (engaging portion) formed in the. A spring 50 that presses the valve body 47 toward the rack shaft 3 is inserted in the valve chamber 4G. An annular groove 51 is formed on the outer periphery of the valve body 47 and communicates with the introduction passage 43 at the neutral position of the rack shaft 3.
When the annular groove 51 is separated from the introduction passage 43 at a non-neutral position of the rack shaft 3, communication through the introduction passage 43 is cut off.

A spool 53 is slidably fitted into the valve hole 52 of the switching valve 45, and an operating rod 54 that is operated by the driver is connected to the spool 53. Negative pressure of the engine and atmospheric pressure are introduced into the front and rear chambers of the valve hole 52 divided by the spool 53, respectively.
The negative pressure of the engine is obtained in an unillustrated intake pipe that supplies air and gasoline to the engine. A communication passage 55 is formed in the spool 53 to communicate the front and rear chambers of the valve hole 52.

The spool 53 is positioned at two positions, and at the forward end of the spool 53, negative pressure from the engine is not guided into the valve hole 52, but atmospheric pressure is passed through the rear chamber of the valve hole 52 and the communication passage 55. is guided to the introduction passage 43, and the spool 53
At the reverse end, atmospheric pressure is not introduced into the valve hole 52, but negative pressure from the engine is introduced into the introduction passage 43 through the front part of the valve hole 52. Atmospheric pressure or negative pressure of the engine introduced into the introduction passage 43 is introduced to the cutoff valve 44 and into the cylinder chamber 32 via a supply passage 56 connected to the introduction passage 43 before the cutoff valve 44 and a suction boat 37. It is meant to be guided. - In the above-described configuration, the diaphragm actuator 40 constitutes the actuation mechanism of the lever 14, and the locking mechanism 3
8. A safety mechanism for the lever 14 is configured by the shutoff valve 44.

Next, the operation will be described based on the above-described configuration. Figure 3 shows the state in which the advancing/retracting iron 30 is retracted, and the lock of the ring gear 9 is released by the retreating of the advancing/retracting port/rotch 30, and the convex portion 12 and the fourth portion 13 are engaged, so that the human power shaft 1 The rotation is directly transmitted to the pinion shaft 2 via the sun gear 11 and the planetary gear arm 6, as shown by the solid line A in FIG. 2, and is transmitted at an increased speed. In the neutral state of the rank shaft 3 in which the valve body 47 is engaged with the recess 49, that is, in the neutral state of the handle, the introduction passage 43 is communicated, and the negative pressure of the engine is introduced to the diaphragm chamber 42, so that the forward and backward rond 30 is connected to the diaphragm actuator 40. is maintained at the retreat end by Next, when the handle is turned, the valve body 47 is removed from the recess 49, and communication with the introduction passage 43 is cut off, so that negative pressure of the engine is no longer introduced into the diaphragm chamber 42. It would be good if the negative pressure of the engine could be maintained in the diaphragm chamber 42 after the communication with the introduction road 43 is cut off, but in reality there is some leakage, so the negative pressure of the engine is maintained in the piston rod 34 of the cylinder chamber 32 even after the communication is cut off. By guiding the piston rod 34 and the engagement groove 35, the reciprocating rod 30 is held at the retracting end by the locking mechanism 38.

When the spool 53 is advanced via the operating rod 54 in a decelerating state of the transmission mechanism in which the advance/retreat rond 30 is retracted and the handle is in a neutral state where the introduction passage 43 can communicate, the piston rods of the diaphragm chamber 42 and the cylinder chamber 32 are moved forward. The negative pressure of the engine was previously introduced to the 34 side, but now atmospheric pressure is introduced. As a result, advance and retreat Roso F'
30 is unlocked, and the lever 14 pivots counterclockwise in the drawing due to the force of the spring. When the handle is in a neutral state, the transmission mechanism can be switched from increasing speed to decelerating or from decelerating to increasing speed, and as a result of turning the lever 14, the engagement between the convex portion 12 and the concave portion 13 is released and the convex portion 12 is engaged with the concave portion 2■. The convex portion 22 engages and the ring gear 9 is locked. As a result, the rotation of the input shaft 1 is transmitted to the pinion shaft 2 via the sun gear 11, the planetary gear 7, and the planetary gear arm 6, as shown by the dashed line B in FIG. 2, and is decelerated by the action of the planetary gear mechanism. Reduce steering force.

When the forward/backward rond 30 is in a decelerating state with the transmission mechanism moving forward and the handle is in a neutral state where communication with the introduction passage 43 is possible, when the handle is turned, the spring 50 is overcome and the valve body 47 retreats, cutting off communication with the introduction passage 43. be done. Even if the spool 53 is moved forward via the operating rod 54 in order to change the speed change mechanism to increase the speed in such a state, the negative pressure of the engine is not introduced into the diaphragm chamber 42 because the communication of the introduction passage 43 is cut off by the cutoff valve 44. No slipping, entrance/exit/throat 3
0 does not work. As a result, it is possible to prevent an under-ramp state in which the engagement between the protrusion 12 and the recess 13 is released and the ring gear 90 is released, and the handle is in an unsteady state in which the handle and the tire are separated. can be prevented from becoming

When the speed change mechanism is in an increased speed state with the advancement/retraction rod 30 retracted and the steering wheel is turned and communication with the introduction passage 43 is cut off,
When the spool 53 is moved backward via the operating rod 54 in order to switch the speed change mechanism to deceleration, the locking mechanism 38 releases the forward/backward rod 30 and the diaphragm chamber 4
If the negative pressure of the engine can be maintained within 2, the forward/reverse rotor l"30
can be held at the backward end, but in reality, there is some leakage, so the advancing/retracting iron 30 moves forward. As a result, the engagement between the convex part 12 and the concave part 3 is released, and the handle is temporarily separated from the tire, leaving the handle unsteady. Since it engages at , it immediately enters a deceleration state.

The above embodiment uses the lock mechanism 38 and the cutoff valve 44 as a safety mechanism, but if the negative pressure of the engine in the diaphragm chamber 42 is to be prevented from leaking, only the cutoff valve 44 may be used.
In this case, the transmission mechanism can maintain its original state even if the switching valve 45 is operated with the steering wheel turned, even though the transmission mechanism is in a deceleration or speed increase state.

In the above-mentioned embodiment, an example has been described in which the rank shaft 3 is provided with an engaging portion that engages with the valve body 47 of the shutoff valve 44, but as another embodiment, a retaining portion may be provided on the pinion shaft. Further, the engaging portion is not limited to a concave portion, but may be a convex portion.

<Effects of the Invention> As described above, in the present invention, an engaging portion is formed on the output shaft, and when the output shaft engaged with this retaining portion is in the neutral state, negative pressure of the engine or atmospheric pressure from the switching valve is applied. The introduction passage is communicated with the diaphragm actuator, and a cutoff valve is installed that cuts off communication with the introduction passage when the output shaft is not in neutral and is not engaged with the engaging part. Even when operated, engine negative pressure or atmospheric pressure from the switching valve is not guided to the diaphragm actuator, allowing the transmission mechanism to remain in its original state.As a result, the steering wheel and tires are separated at the location of the transmission mechanism. can avoid being dizzy.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 shows the lever operating mechanism and safety mechanism, which are the main parts of the invention, and
The figure is a cross-sectional view showing a steering gear used as an example of the embodiment of the present invention, FIG. 3 is a cross-sectional view taken along line mm in FIG. 2, and FIG. 4 is a cross-sectional view taken along line IV-■ in FIG. ...Input shaft, 2... Binion shaft, 3... Rack shaft, 5... Gear box, 6... Planetary gear arm, 7...
... Planet gear, 9 ... Ring gear, 10 ... Spline, 11 ... Sun gear, 12 ... Convex part, 13 ...
・Concavity, work 4... lever, I8... connecting rod, 20.
... Spring, 1... Concave portion, 22... Engagement convex portion,
30... Advance/retreat rond, 35... Engagement groove, 38...
Lock mechanism, 40... diaphragm actuator, 4
3...Introduction passage, 44...Shutoff valve, 45...Switching valve, 56...Supply passage.

Claims (1)

[Claims] (1) A speed change mechanism is provided between the input shaft on the steering wheel side and the output shaft on the steering gear side, and the speed change mechanism is configured to decelerate or speed up the rotation of the input shaft and transmit it to the output shaft. In a steering force switching device equipped with a switching lever, one end of the lever is connected to a diaphragm of a diaphragm actuator in order to rotate the lever, an introduction passage communicating with a diaphragm chamber of the diaphragm actuator is provided, and the steering force is guided to the introduction passage. Provided with a switching valve that turns on and off the negative pressure of the engine by operation of the driver, forming an engaging part on the output shaft, and communicating with the introduction passage when the output shaft engaged with the engaging part is neutral; A safety mechanism for a steering force switching device, characterized in that a cutoff valve is provided that cuts off communication with an introduction passage when an output shaft that is not engaged with an engagement portion is in a non-neutral state.