JPH07117096B2 - Board Wire - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Bowden wire in which a wire is inserted into a flexible outer tube and a driving force is transmitted by relative movement of the outer tube and the wire. It is a thing.

(Background of the Invention) There is an engine in which an exhaust system is provided with an exhaust control valve for changing an exhaust passage area. For example, by providing this near the opening end of the exhaust pipe to the expansion chamber, the exhaust flow passage area is reduced in the rotational speed range where dynamic effects such as the inertial effect and the pulsating effect of the exhaust system act to reduce the volume efficiency. , There is one that aims to improve the output characteristics by eliminating the influence of the dynamic effect (Japanese Patent Application No. 60-263752).
issue). It is also known to close an exhaust control valve in a multi-cylinder engine in a speed range where exhaust interference between cylinders adversely affects (Japanese Patent Application No. 60-263753).

Further, there is also one in which an exhaust control valve is provided in order to improve the combustion by controlling the back pressure of the exhaust pipe or to use as an exhaust brake.

As described above, the exhaust control valves provided for various purposes are always exposed to high-temperature exhaust, so that heat is also transmitted to the drive system thereof. For example, it is conceivable to fix a pulley to the valve shaft of this exhaust control valve and drive this pulley by Bowden wire. However, in this case, heat is transferred to the Bowden wire, so a special one with excellent heat resistance must be used,
The problem of becoming expensive arises. In addition, an inexpensive ordinary Bowden wire has a liner made of molybdenum-containing polypropylene resin attached to the inner surface of the outer tube for the purpose of reducing the sliding resistance of the wire, but this liner has a problem that it is easily melted by heat. However, if this liner is omitted altogether, the sliding resistance of the wire will increase.

Such a problem may occur not only when the hot member is driven by the Bowden wire but also when the Bowden wire is arranged close to the hot member.

(Object of the Invention) The present invention has been made in view of such circumstances, and is suitable for driving a high temperature member or arranging in the vicinity of a high temperature member, is inexpensive, and has an excessive sliding resistance of the wire. It is intended to provide a Bowden wire that never becomes.

(Structure of the Invention) According to the present invention, an object of the present invention is to provide a plurality of kinds of flexible outer tubes connected in the length direction and one wire inserted through these outer tubes. Bowden wire, characterized in that the liner is not interposed between the outer tube and the wire as the outer tube having excellent heat resistance, and the liner is interposed between the outer tube and the other wire, Achieved by

(Embodiment) FIG. 1 is a partial sectional view of an embodiment of the present invention, FIGS. 2 and 3 are sectional views taken along the lines II-II and III-III, and FIG. 4 is an exhaust of this Bowden wire. FIG. 5 is a side view showing an application example used for driving a control valve, FIG. 5 is a side view showing a state where a cover of the pulley is attached, FIG. 6 is a plan sectional view of an exhaust control valve, and FIG. It is a side view of a two-wheeled vehicle.

In FIG. 7, reference numeral 10 is a 4-cycle 4-cylinder engine, which is mounted near the center of the vehicle body. The engine 10 has a cylinder 14 extending obliquely upward and forward from a crankcase 12. The exhaust system is connected to the four exhaust pipes 16 (16a to 16d) extending from the front surface of the cylinder 14 to the lower side of the crankcase 12 and the rear end of the exhaust pipes 16, and collects the exhaust gas of each exhaust pipe 16 to silence the silencer. And an exhaust control valve 20 leading to 18.

As shown in FIG. 6, a body 22 of the exhaust control valve 20 is connected to each of the four exhaust pipes 16 and forms branch pipes 24 (24a to 24d) together with the exhaust pipes 16, and the branch pipes 24. An expansion chamber 26 in which the downstream open ends 16A to 16D of 24 and one collecting pipe portion 27
And are integrally cast from stainless cast steel. Each branch end of the branch pipe portion 24 on the upstream side is connected to each exhaust pipe 16. Further, the downstream opening end 16 of the branch pipe 24
Each of A to 16D has a vertically long quadrangular opening shape and opens in parallel with the expansion chamber 26. A connecting pipe 27a is integrally connected to the collecting pipe portion 27, and the silencer 18 is detachably connected to the rear end of the connecting pipe 27a by a fastener so that only the silencer 18 can be replaced. .

Reference numeral 28 denotes a crank-shaped valve body (FIG. 6). Both ends of the valve body 28 are rotatably supported by the left and right walls of the expansion chamber 26 behind the open ends 16A to 16D, and the intermediate portion 30 thereof is It is formed in an arc shape in cross section. Circular openings are formed in the left and right walls of the expansion chamber 26,
These openings are used for the bearing plate 3 as a support member for the valve shafts 28a and 28b.
It is closed at 2, 34. The valve shafts 28a and 28b at both ends of the valve body 28 are axially supported by bearing plates 32 and 34, respectively, and one valve shaft 28a penetrates the bearing plate 32 and projects outward, and the pulley 36 is fixed to the projecting ends. There is. The intermediate portion 30 of the valve body 28 faces the downstream opening of the branch portion 24, that is, the downstream opening ends 16A to 16D of the exhaust pipe 16. The outer peripheral surface of the intermediate portion 30 and the exhaust pipe 16
The downstream open ends 16A to 16D are formed in an arc shape centered on the valve shafts 28a and 28b and are close to each other. The pulley 36 is rotated by a servomotor (both not shown) via two Bowden wires 38, 38 described later in accordance with the rotation speed of the engine 10, and the exhaust control valve 20 is, for example, a low / medium speed engine 10. It is controlled to close at high speed and open at high speed.

As shown in FIG. 1, the Bowden wire 38 includes two types of outer tubes 40 and 42, and a wire 44 inserted through them. The outer tube 40 has excellent heat resistance, and as shown in Fig. 2, a free tube 40 in which a steel wire is spirally wound.
and a coating 40b of the universal tube 40a. This coating 40b
Is made of polypropylene with excellent heat resistance. The outer tube 42 is a relatively inexpensive one that has been widely used in the past, and as shown in FIG. 3, a free tube 42a in which a steel wire is spirally wound, a cover 42b, and a liner 42c inserted in the free tube 42a. With. The coating 42b is made of cheap polyvinyl chloride, and the liner 42c is made of molybdenum-containing polyethylene.

These two kinds of outer tubes 40, 42 are caulked and connected to each other by a joint 46 made of a metal tube.

The bearing plate 32 on the left side of the exhaust control valve 20 has a wire receiver 48.
Are fastened together, and the end portion of the outer tube 40 having excellent heat resistance is attached to the wire receiver 48 via the wire guide 50. That is, the wire guide 50 is made relatively long, and the heat transferred from the wire receiver 48 to the outer tube 40 is radiated here to prevent the outer tube 40 from overheating. The wire guide 50 is crimped to the end portion of the outer tube 40 so as to be freely rotatable, so that heat transfer from the wire guide 50 to the outer tube 40 is reduced. The wire guide 50 is mounted as shown in FIG. 4, and is attached to the wire receiver 48 by a stopper 50a (see FIG. 1) formed in the wire guide 50 and a clip 52 mounted in the annular groove 50b so as to freely rotate. Has been. This is also to reduce heat transfer. In FIG. 1, 54 is an adjusting nut for adjusting the length of the outer tube 42, and 56 is also an adjusting bolt. Reference numeral 58 is a protector attached to the outer tube 42.

Two Bowden wires 38 thus constructed are attached as shown in FIG. 4, and the two wires 44, 44 are locked to the pulley 36. The other ends of the wires 44, 44 are connected to the servomotor as described above.

A cover 60 covers the pulley 36, and is screwed to the three bosses 32a protruding from the bearing plate 32. This boss 32a
Protrudes from the side surface of the bearing plate 32, and a gap is formed between the cover 60 and the bearing plate 32. Cooling air is covered from this gap 60
It flows in and is discharged from the opening of the cover 60 that surrounds the wire receiver 48.

In FIG. 5, 62 is a front wheel, 64 is a steering wheel, 66
Is a fuel tank, 68 is a driving seat, and 70 is a rear wheel.

Therefore, when the diameter and length of the exhaust pipe 16 are set so that the volumetric efficiency of the engine 10 is high in the high speed range, the exhaust control valve 20 is controlled to close in the low and medium speed range and open in the high speed range. It is driven by a motor.

The positive pressure wave due to the opening of the exhaust valve of the engine 10 propagates in the exhaust pipe 16 at the speed of sound, and the negative pressure wave generated by the rapid expansion at the opening ends 16A to 16D causes the exhaust pipe 16 to travel in the opposite direction at the speed of sound. And propagates back to the exhaust valve of the engine 10. If the exhaust control valve 20 located near the open ends 16A to 16D is closed, a positive pressure wave due to the opening of the exhaust valve will cause this exhaust control valve 20
It is reflected by and returns to the exhaust valve at the speed of sound as a positive pressure wave.
Therefore, the exhaust control valve 20 is designed to reduce the exhaust flow passage area to about 1/2 in the medium speed range where the dynamic effect works in reverse to reduce the volume efficiency.
If the control is performed, the sum of the negative pressure wave generated by the open end of the exhaust pipe and returning and the positive pressure wave reflected by the exhaust control valve 20 becomes zero. At this time, the pulsating effect is canceled out, and a decrease in volume efficiency (occurrence of a torque valley) in the medium speed range can be suppressed.

Further, when the exhaust control valve 20 is used for the purpose of preventing the torque reduction due to the exhaust interference between the cylinders, the exhaust control valve 20 may be closed in the rotation region where the torque reduction due to the exhaust interference is remarkable.

The outer tube 40 has good heat resistance because the coating 40b is made of a material having high heat resistance, and the liner is omitted, so that the heat resistance is even better. Since the liner 42c is attached to the other outer tube 42, the sliding resistance of the wire 44 does not become excessive.

In this embodiment, two outer tubes 40 and 42 are used, but three or more outer tubes are used, and only the outer tube in the vicinity of the high heat component has high heat resistance, and the others are inexpensive. You may

(Effects of the Invention) The present invention uses a plurality of types of outer tubes as described above and makes a part of the outer tubes of high heat resistance, and a liner having poor heat resistance is interposed between the tubes and the wires. Since it is not performed, it is suitable for driving a high temperature member or arranging it close to a high temperature member, and the heat resistant material is inexpensive because it is used only partially. Moreover, since the outer tube having good heat resistance is used only partially, and the liner is interposed between the outer tube and the wire other than that, the sliding resistance of the wire does not become excessive.

[Brief description of drawings]

FIG. 1 is a partial sectional view of an embodiment of the present invention, FIGS. 2 and 3 are sectional views taken along lines II-II and III-III, and FIG. FIG. 5 is a side view showing a state where the pulley cover is mounted, FIG. 6 is a plan sectional view of an exhaust control valve, and FIG. 7 is a side view of a motorcycle using the same. Is. 38 …… Boden wire, 40,42 …… Outer tube, 44 …… Wire, 42c …… Liner.

Claims (1)

[Claims] 1. A plurality of types of flexible outer tubes connected in a length direction and a wire inserted through these outer tubes are provided, and a part of the outer tubes is made heat resistant. A Bowden wire, which is characterized in that a liner is not interposed between the wire and the other outer tube, and a liner is interposed between the outer tube and the wire.