JPH063144Y2 - Positioning structure for auxiliary valve of exhaust control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a positioning structure of an auxiliary valve in an exhaust control device of a two-cycle engine in which a piston itself acts as an exhaust valve.

(Prior Art) Conventionally, in a two-cycle engine, an auxiliary exhaust passage is provided in addition to the main exhaust passage, the auxiliary exhaust passage is closed at low speed, the auxiliary exhaust passage is opened at high speed, and the cross sectional area of the exhaust passage is There is an exhaust device in which the output at high speed is improved by making the area corresponding to the rotation speed of the engine (for example, refer to JP-A-60-249614). An example of the exhaust device is shown in FIGS. 5 and 6.

In FIG. 5, two auxiliary valves 4 and 5 are provided in an auxiliary exhaust passage 3 that auxiliary connects the cylinder 1 and the main exhaust passage 2 thereof. These auxiliary valves 4 and 5 are
It is a rotary valve that has valve bodies 4a and 5a and valve passages 4b and 5b and is bidirectionally rotatable. The auxiliary valves 4 and 5 have valve pinions 4c and 5c which directly or indirectly engage with the drive rod 6 of FIG. 6, and are rotated by the drive rod 6 so that the auxiliary exhaust passage 3 of FIG. Open and close. A connecting member 7 is fixed to the right end portion of the drive rod 6 in FIG. 6, and an actuator 8 is connected via the connecting member 7. The actuator 8 slides the drive rod 6 in the axial direction according to the change in the rotation speed of the engine. 9 is a stopper at low speed, 1
Reference numeral 0 denotes a stopper at high speed, which is fixed to the engine body 11 and contacts the left end surface 6a of the drive rod 6 or the step portion 6b on the right side to position the drive rod 6 at low speed or high speed.

In this prior art, by increasing the positioning accuracy, the positioning accuracy is improved at the low speed in FIG. 5, that is, when the auxiliary valves 4 and 5 are fully closed, and when not fully shown. . Thus, when fully closed, for example, the valve bodies 4a, 5a and the passage wall 8a are accurately overlapped to prevent the passage wall 3a from becoming unnecessarily thick. On the other hand, when the valve is fully opened, for example, the valve bodies 4a and 5a do not block the flow of exhaust gas.

(Problems to be solved by the invention) However, in the above-mentioned conventional technique, the dimension D1 from the left end face 6a of the drive rod 6 to the right step 6b of FIG. 6 and two stoppers connected to the engine body 11 are provided. The positioning accuracy is determined by the dimension D2 between 9 and 10. Therefore, it is necessary to increase the accuracy of the dimension D2 in the large engine body 11 as well as in the small drive rod 6, so that the workability, that is, the manufacturability is inconvenient.

The present invention has been made to solve the above-mentioned conventional inconvenience, and an object thereof is to provide an auxiliary valve positioning structure having excellent manufacturability in an exhaust control device.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the present invention first provides a first and a second abutment on both side surfaces of a bearing device which is fixed to an engine body and axially supports a drive rod. Parts are formed. On the other hand, the step portion of the drive rod and the connecting member fixed to the drive rod come into contact with the first and second contact portions to position the drive rod.

(Operation) According to the present invention, the positioning accuracy of the drive rod is determined by the dimension between the two side surfaces of the bearing device and the dimension from the step portion to the connecting portion of the drive rod. Therefore, the dimensional accuracy of the bearing device, which is a small component, and
By increasing the accuracy of the fixed position of the connecting member, which is also a small component, with respect to the drive rod, the positioning accuracy of the drive rod is improved, and the manufacturability is good.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, the drive rod 6 is inserted into a sliding hole 12 formed in the engine body 11 so as to be movable left and right, and is driven by an actuator 8 on the right side in response to an increase in the rotational speed of the engine. , Move to the right. Connecting member 7
Is for connecting the drive rod 6 and the actuator 8 and is fixed to the drive rod 6 by, for example, two E rings 13 and has a pair of flange portions 7a. The left end of the drive rod 6 is pivotally supported in the sliding hole 12,
On the other hand, the right end portion thereof is pivotally supported by the bearing device 14. This bearing device 14 has a male screw 16 through a plate 15.
Is fixed to the engine body 11, and recesses 14a and 14b are bored from both end surfaces thereof. This bearing device 14
The inner side surface of the recess 14a on the left side of the first contact portion 14c on which the step portion 6b on the right side of the drive rod 6 contacts at the time of high speed.
Are configured. On the other hand, the right end surface of the bearing device 14 has a second contact portion 14d with which the connecting member 7 contacts at low speed.
Are configured. An oil seal 17 is housed in the recess 14b on the right side.

The drive rod 6 is provided with a first rack 6c that engages with the left valve pinion 4c and a second rack 6d that engages with the pinion 18. Above pinion 18
Is rotatably supported by the engine body 11 by the shaft portion 18a of FIG. 2, and is also engaged with the right valve pinion 5c as shown in FIG. Therefore, as the drive rod 6 moves to the right due to the operation of the actuator 8, the two valve pinions 4c and 5c rotate and the auxiliary valves 4 and 5 in FIG. 5 are opened.

In FIG. 2, the auxiliary valves 4 and 5 are the valve bodies 4
a, 5a, the valve pinions 4c, 5c, cylindrical portions 4d, 5d, and shaft portions 4e, 5e are integrally formed, and are rotatably supported by the engine body 11. A left side 19 is a cap that closes the left end of the sliding hole 12 and has a gap S between the left end surface 6a of the drive rod.

Next, the actuator 8 will be described.

A vertical pin 39 of the rotating arm 38 is engaged between the flange portions 7a of the connecting member 7. The vertical rotation shaft 40 fixed to the lower surface of the rotation arm 38 is rotatably supported by the boss member 58 of the engine body 11 shown in FIG. It is fixed to the arm 42 shown in FIG. Pin 4 that rotatably supports this arm 42
1 is sandwiched between a pair of annular adjuster plates 44 of the slider 43. Therefore, when the slider 43 moves to the left, the arm 42 and the vertical rotation shaft 40 are moved.
And the rotating arm 38 rotates clockwise about the vertical rotating shaft 40.

The slider 43 is axially slidably fitted on the governor rotating shaft 45 of the governor device 30 shown in FIG. The governor device 30 is a so-called centrifugal ball type governor device including a steel ball 48 sandwiched between a pair of dish-shaped spherical plates 46 and 47, a governor spring 49 and the like. The right spherical plate 46 is fixed in the axial direction, while the left spherical plate 47 is integrally formed with the slider 43. The governor spring 49 is provided in a compressed state between the adjuster plate 44 and the governor drive gear 51, and always presses the spherical plate 47 to the right. The drive gear 51 is fixed to the governor rotating shaft 45 and is engaged with the gear 56 fixed to the crankshaft 55.

The other configurations are the same as those of the conventional example, and the same portions or corresponding portions are denoted by the same reference numerals and detailed description thereof will be omitted.

Next, the operation of the above configuration will be described.

First, when the engine rotational speed is low and low, that is, when the centrifugal force acting on the steel balls 48 is small, the slider 43 is pressed to the right by the spring force of the governor spring 49. For this reason, a counterclockwise rotational force is applied to the rotating arm 38 shown in FIG.
4 is kept in contact with the second contact portion 14d. Therefore, since the auxiliary exhaust passage 3 in FIG. 5 is closed by the auxiliary valves 4 and 5, the cross-sectional areas of all the exhaust passages 2 and 3 are small corresponding to low speed.

After that, when the rotation speed of the engine increases to a predetermined speed, a large centrifugal force acts on the steel ball 48 due to the high speed rotation of the governor rotation shaft 45 in FIG.
And moves to the left along the inclination of the spherical plate 46. At the same time, the slider 43 moves to the left, and the arm 42, the vertical rotating shaft 40, and the rotating arm 38 shown in FIG. 4 rotate clockwise around the vertical rotating shaft 40. By this rotation, the drive rod 6 gradually moves to the right through the connecting member 7 of FIG. 1, and with this movement,
The pinion 18 and the left valve pinion 4c are each rotated clockwise. At this time, the valve pinion 5c on the right side is rotated counterclockwise by the pinion 18. Therefore, the auxiliary valves 4 and 5 in FIG. 5 are rotated and the auxiliary exhaust passage 3 is opened.

After that, when the engine speed reaches a predetermined high speed,
The step portion 6b on the right side of the drive rod 6 in FIG.
4, the drive rod 6 stops moving, and the auxiliary valves 4 and 5 in FIG. 5 are fully opened. Therefore, since the cross-sectional areas of all the exhaust passages 2 and 3 are large corresponding to the high speed, as is well known, the output of the engine at the high speed is improved.

In the above structure, the present invention is directed to the bearing device 14 of FIG.
First and second contact portions 14c and 1 which are both side surfaces of
The step portion 6b on the right side of the drive rod 6 and the left end surface of the connecting member 7 come into contact with 4d, respectively, and the moving end of the drive rod 6 at high speed and low speed is positioned. That is,
The rotary ends of the auxiliary valves 4 and 5 of FIG. 5 are positioned.
Therefore, the positional accuracy of the fully closed and fully opened auxiliary valves 4 and 5 is determined by the dimension D3 of the bearing device 14 shown in FIG.
And the dimension D4 from the step 6b on the right side to the connecting member 7
Depends on Therefore, by increasing the dimensional accuracy of the bearing device 14, which is a small component, and the accuracy of the fixing position of the connecting member 7, which is also a small component, with respect to the drive rod 6, all of the auxiliary valves 4 and 5 of FIG. Since the positional accuracy at the time of closing and fully opening can be made high, in other words, the dimensional accuracy of the bearing device 14 and the accuracy of the fixed position of the connecting member 7 with respect to the drive rod 6 can be made extremely simple and easy with special skill. Since it is possible to increase the height of the exhaust control device without requiring the property and the device, the productivity of the exhaust control device is improved.

Further, the connecting member 7 and the like in FIG. 1 have been conventionally used. Therefore, there is no fear that the structure will be complicated.

In addition, although the mechanical type is used as the actuator 8 in the above embodiment, an electric type may be used. For example, a well-known actuator that is operated by a motor by detecting the number of revolutions of the engine (not shown) may be used.

(Effects of the Invention) As described above, according to the present invention, the step portion of the drive rod and the connecting member come into contact with both side surfaces of the bearing device,
Since the moving end of the drive rod, that is, the rotating end of the auxiliary valve is positioned, there is no need to use special skill or special equipment to improve the processing accuracy, and the processing accuracy is extremely easy and easy. Can be increased. Therefore, the manufacturability of the exhaust control device can be improved without increasing the cost. Further, since the positioning structure is constructed by using the drive rod, the bearing device and the connecting member which are indispensable as the exhaust control device, there is no fear that the structure will be complicated as compared with the conventional structure.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a plan sectional view of an essential part of an exhaust control device at low engine speed, FIG. 2 is a longitudinal sectional view of the same, and FIG. 3 is a longitudinal sectional view of an actuator 8. Four
FIG. 5 is a plan view of the actuator 8, FIG. 5 is a plan sectional view of an exhaust system to which the present invention is applied, and FIG. 6 is a plan sectional view of a conventional exhaust control system. 1 ... Cylinder, 2 ... Main exhaust passage, 3 ... Auxiliary exhaust passage,
4, 5 ... Auxiliary valve, 6 ... Drive rod, 6b ... Step portion, 7
... connecting member, 8 ... actuator, 11 ... engine main body, 14 ... bearing device, 14c ... first contact portion, 14d ...
Second contact portion.

Claims (1)

[Scope of utility model registration request] 1. A positioning structure for an auxiliary valve of an exhaust control device for positioning a rotating end of an auxiliary valve provided in an auxiliary exhaust passage for auxiliary communication between a cylinder and its main exhaust passage, wherein A drive rod that engages and rotates the drive rod, a bearing device that is fixed to the main body of the engine and that axially supports the drive rod, and slides the drive rod in the axial direction according to changes in the rotational speed of the engine. An actuator for moving the driving rod, and a step portion is formed on the drive rod, and a connecting member connected to the actuator is fixed to the drive rod, and one side surface of the bearing device is brought into contact with the step portion. A first contact portion for performing first axial positioning of the drive rod is formed, and the other side surface of the bearing device is brought into contact with the connecting member to allow the shaft of the drive rod to come into contact. Positioning structure of the auxiliary valve of the exhaust control device characterized by forming a second contact portion for performing a second positioning direction.