JPH0320507Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an opening/closing mechanism for an intake shutter which is pivotally supported in an intake passage by an eccentric shaft so that the valve closes in conjunction with the operation of the exhaust brake and also closes when the engine reverses rotation.

The intake shutter is pivotally supported in the intake passage of a diesel engine by an eccentric shaft, and when the engine rotates in the forward direction, the valve opens due to the intake air flow, and when the engine rotates in reverse, the valve closes due to the exhaust backflow, thereby preventing the engine from reversing. Reversal prevention devices are already known (Utility Model Application No. 56-11336, Utility Model Application No. 11336)
(Refer to Publication No. 54242 and Japanese Utility Model Application Publication No. 142241/1983).

Furthermore, in diesel engines equipped with an exhaust brake, an intake shutter is provided in the intake passage to prevent noise when the exhaust brake is activated.

An example of this is shown in FIGS. 1 and 2. For example, a push rod 8 of a diaphragm type actuator 5 operated by boost pressure is axially connected to a rotating lever 18, and the rotating lever 18 is connected to a axially connecting portion 21. The intake shutter 3 rotates around a support shaft 2 of an eccentric intake shutter 3, and the intake shutter 3 is attached to the support shaft 2.
Reference numeral 22 indicates a stopper for the maximum opening of the intake shutter 3, and 23 indicates a stopper for the maximum closing of the intake shutter.

Now, if you operate the operating lever (not shown) to operate the exhaust brake,
For example, the actuator of the exhaust brake is actuated by the boost pressure to close an exhaust shutter (not shown) provided in the exhaust passage. At the same time, the actuator 5 is operated and the push rod 8 is retracted in the direction of the arrow.
8 rotates in the direction of the arrow to close the intake shutter 3.

However, with the structure in which the push rod 8 of the actuator and the rotating lever 18 are connected together 21, a moment inevitably acts, and an unreasonable force acts on the push rod 8, the lever 18, and the shutter support shaft 2, and furthermore, the actuator 5 is An unreasonable force will act on it. Furthermore, with the structure in which the push rod 8 of the actuator 5 and the rotary lever 18 are connected 21 in a shaft, the intake shutter 3 cannot be automatically closed due to backflow of exhaust gas when the engine is reversed.

Therefore, an object of the present invention is to provide a valve that can close the intake shutter when the exhaust brake is activated without applying excessive force to each member or actuator of the intake shutter opening/closing mechanism. Another object of the present invention is to provide an intake shutter opening/closing mechanism that automatically closes the intake shutter due to backflow of exhaust gas when the engine is reversed, thereby preventing the engine from reversing.

Therefore, according to the present invention, in the opening/closing mechanism of the intake shutter, which is pivotally supported in the intake passage by an eccentric shaft so as to close the valve in conjunction with the exhaust brake operation and to close the valve when the engine reverses, the intake shutter is A guide lever equipped with a stopper bolt of the intake shutter is fixed to the push rod of the actuator that opens and closes, intersecting with the push rod, and a guide bolt is provided parallel to the push rod to guide the guide lever, so that the guide lever can be guided as the push rod moves back and forth. The lever is configured to reciprocate along the guide bolt, and is provided with a locking member that rotates about the support shaft of the intake shutter and that the stopper bolt abuts at a position eccentric to the support shaft of the intake shutter. There is provided an opening/closing mechanism for an intake shutter provided in an intake passage of a diesel engine, characterized in that a rotary lever is provided, and the actuator is operated to close the intake shutter when an exhaust brake is operated.

In this way, the guide lever, which always moves parallel to the actuator push rod while being guided by the guide bolt, is secured to the push rod by crossing it, and the stopper bolt attached to it is rotated around the fulcrum of the intake shutter. The structure is such that it comes into contact with a locking member attached to the lever, so when the actuator is operated and the intake shutter is closed when the exhaust brake is activated, there is no excessive force on the push rod, rotating lever, shutter spindle, or even the actuator. does not work. In addition, since the rotary lever allows the intake shutter to rotate in the valve closing direction independently of the actuator, the intake shutter can be automatically closed by exhaust backflow when the engine is reversed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In FIGS. 3 to 5, an intake shutter 3 is pivotally supported by a shutter support shaft 2 provided eccentrically with respect to an intake passage 1 of the engine. This intake shutter 3 automatically opens in response to the intake air flowing through the intake passage 1 when the engine rotates in the forward direction, and automatically closes in response to the exhaust backflow flowing within the intake passage 1 when the engine rotates in reverse. speak. An intake shutter opening/closing mechanism, generally indicated by 4, is provided, which closes the intake shutter 3 together with an exhaust shutter provided in an exhaust passage (not shown) when the exhaust brake is activated.

In the illustrated example, a diaphragm type actuator 5 operated by boost pressure is used as the power source for closing the intake shutter 3, and the actuator 5 is attached to the intake shutter unit body 7 by a bracket 6. There is. A push rod 8 extends from the actuator 5 and is integrally attached to a diaphragm (not shown) of the actuator 5, and the push rod 8 is connected to a bracket 1 attached to the main body 7 by bolts.
It is slidably supported by 0. A bush 11 made of resin is fitted into the portion of the bracket 10 through which the push rod 8 passes.

A guide lever 12 is fixed to a relatively distal portion of the push rod 8 so as to intersect with the push rod 8. A guide bolt 13 that also serves as a stopper is threaded onto the bracket 10 in parallel with the push rod 8. The bolt head 13a of the guide bolt 13 serves as a stopper for regulating the amount of movement of the guide lever 12. A nut 14 is screwed into the base. This guide bolt 13 which also serves as a stopper passes through the guide lever 12, and the guide lever 12 reciprocates along the guide bolt 13 as the push rod 8 reciprocates. Guide bolt 13 of guide lever 12
A bushing 15 made of resin is fitted into the portion that comes into sliding contact with. A stopper bolt 16 is screwed onto the opposite side of the guide lever 12 from the guide bolt 13 which also serves as a stopper.The bolt head 16a of the stopper bolt 16 abuts against a locking member 19 provided on a rotary lever 18, which will be described later, so that the maximum intake shutter In addition to regulating the opening degree, the locking member 1 is used when the exhaust brake is activated.
9 is pressed to rotate the rotation lever 18 and close the intake shutter 3. A nut 17 is screwed into the base of the stopper bolt 16.

A rotary lever 18 is provided which rotates around the support shaft 2 of the intake shutter 3, and a locking member 19 is fixed to the rotary lever 18 at a position eccentric to the support shaft 2. A head 16a of a stopper bolt 16 provided on the guide lever 12 is in contact with this locking member 19. Additionally, in FIG. 5, reference numeral 20 denotes a bush provided at the portion where the support shaft 2 of the intake shutter 3 passes through the main body 7.

Next, the operation will be explained. When the exhaust brake is not operated, the intake shutter 3 receives the intake air flowing through the intake passage 1, and the locking member 19 engages the bolt head 16 of the stopper bolt 16.
The valve opens at the position where it abuts a. When the engine reverses, the intake shutter 3 rotates in the direction of the arrow and closes due to the backflow of exhaust gas flowing through the intake passage 1, thereby preventing the engine from reversing.

Now, when a control lever (not shown) is operated to operate the exhaust brake, for example, the actuator of the exhaust brake is actuated by the boost pressure to close the exhaust shutter (not shown) provided in the exhaust passage.
At the same time, the actuator 5 operates and the push rod 8 contracts in the direction of the arrow, whereby the stopper bolt 16 pushes the locking member 19 via the guide lever 12, and the rotary lever 18 rotates in the direction of the arrow to close the intake shutter. 3 closes. that time,
The guide lever 12 moves along the guide bolt 13 which also serves as a stopper, so it always maintains a parallel state.
Since the force from the actuator 5 is transmitted to the rotating lever 18 in the contact relationship between the stopper bolt 16 and the locking member 19, the force from the actuator 5 is transmitted to the push rod 8, the rotating lever 18, the shutter support shaft 2, and the actuator 5. No excessive force is applied. In addition, since the rotation lever 18 allows the intake shutter 3 to rotate in the valve closing direction independently of the actuator 5 side, the intake shutter 3 automatically closes due to exhaust backflow when the engine is reversed. Therefore, it is possible to prevent the engine from reversing.

The stroke of the push rod 8 can be adjusted by operating the nut 14 of the guide bolt 13 which also serves as a stopper.
To adjust the opening/closing degree, use the nut 17 of the stopper bolt 16.
This can be done by operating the .

As explained above, according to the present invention, when the actuator is operated to close the intake shutter when the exhaust brake is activated, no excessive force is applied to the opening/closing mechanism of the intake shutter, and when the engine is reversed, The intake shutter can be closed to prevent the engine from reversing without any manual operation.

[Brief explanation of the drawing]

1 and 2 show a conventional intake shutter opening/closing mechanism, with FIG. 1 being a plan view and FIG. 2 being a side view showing a section of the shutter shaft. 3 to 5 show the opening/closing mechanism of the intake shutter according to an embodiment of the present invention, FIG. 3 is a perspective view, FIG. 4 is a plan view, and FIG. 5 is a cross-sectional view of the shutter shaft portion. FIG. 1... Intake passage, 2... Shutter support shaft, 3...
Intake shutter, 4... Intake shutter unit, 5... Actuator, 8... Push rod, 10... Bracket, 12... Guide lever, 13... Guide bolt that also serves as a stopper, 1
6... Stopper bolt, 18... Rotating lever, 1
9...Locking member.

Claims (1)

[Scope of utility model registration request] In the opening/closing mechanism of the intake shutter, which is pivotally supported in the intake passage by an eccentric shaft so that the valve closes when the exhaust brake is applied and also closes when the engine reverses, the push rod of the actuator that opens and closes the intake shutter intersects with the opening/closing mechanism of the intake shutter. A guide lever equipped with a stopper bolt of the intake shutter is fixed, and a guide bolt is provided parallel to the push rod to guide the guide lever, so that the guide lever reciprocates along the guide bolt as the push rod reciprocates. The exhaust brake includes a rotary lever that rotates about the support shaft of the intake shutter and has a locking member that the stopper bolt comes into contact with at a position eccentric to the support shaft of the intake shutter. What is claimed is: 1. An intake shutter opening/closing mechanism provided in an intake passage of a diesel engine, characterized in that when activated, an actuator operates to close the intake shutter.