JP4188397B2 - Engine intake system - Google Patents

Description

  The present invention relates to a throttle body having an intake passage, a throttle valve that is attached to a valve shaft that is rotatably supported by the throttle body, and that opens and closes the intake passage, and detects the rotation angle of the valve shaft as the opening of the throttle valve. The present invention relates to an improvement in an intake device for an engine, which includes a throttle sensor for detecting the intake air temperature, an intake air temperature sensor for detecting an intake air temperature, and a boost negative pressure sensor for detecting a boost negative pressure in an intake passage downstream of the throttle valve.

2. Description of the Related Art Conventionally, an intake device for an engine, in which a bypass passage that bypasses the throttle valve and is connected to the intake passage is formed in the throttle body, a bypass valve that opens and closes the bypass passage, and an actuator that drives the opening and closing of the bypass passage is provided. Is already known as disclosed in Patent Document 1. In addition, a throttle sensor that detects the opening of the throttle valve, an intake air temperature sensor that detects the temperature in the intake passage, a boost negative pressure sensor that detects the boost negative pressure in the intake passage, etc. are installed in the throttle body in order to detect the operating state of the engine. Also known is the intake system of the installed engine.
Japanese Utility Model Publication No. 6-45654

  In a conventional engine intake system, a throttle sensor, an intake air temperature sensor, and a boost negative pressure sensor are attached to the throttle body itself. The parts must be assembled to the throttle body itself, and there are drawbacks such as poor assembly.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an intake device for an engine that includes a throttle sensor, an intake air temperature sensor, and a boost negative pressure sensor, and has good workability and ease of assembly. And

In order to achieve the above object, the present invention provides a throttle body having an intake passage, a throttle valve attached to a valve shaft rotatably supported by the throttle body to open and close the intake passage, and a rotation angle of the valve shaft. In an intake system for an engine, comprising: a throttle sensor that detects the opening of the throttle valve; an intake air temperature sensor that detects intake air temperature; and a boost negative pressure sensor that detects boost negative pressure in the intake passage downstream of the throttle valve The device block joint surface is detachably joined to a flat mounting surface formed in parallel to the intake passage axis on the throttle body. The device block includes a throttle sensor, an intake air temperature sensor, and a boost negative pressure sensor. the attached, these sensors, the intake air temperature sensor from the upstream side of the intake passage, a throttle sensor , Arranged along the axis of the intake path in the order of the boost negative pressure sensor, the device block, an outer surface opposite to the bonding surface, to form a housing hole for housing the boost negative pressure sensor, the junction on the surface, mounting a communicating groove for communicating the downstream of the intake passage from the throttle valve facing the sensing portion of the boost negative pressure sensor, forming a seal groove surrounding the communicating groove, the sealing member to the seal groove characterized in that it was.

According to the present invention, the joint surface of the device block is detachably joined to the flat attachment surface formed in parallel to the axis of the intake passage on the throttle body, and the throttle sensor, the intake air temperature sensor is connected to the device block. and so fitted with boost negative pressure sensor, throttle sensor to the device blocks, the mounting of the intake air temperature sensor and the boost negative pressure sensor can be performed in parallel with the assembly of the throttle body side, to improve the productivity be able to. In addition, by removing the device block from the throttle body, the various sensors can be easily maintained. In addition, by changing the specifications of the various sensors in the device block, it is possible to easily provide an intake device for an engine with different specifications while using the same throttle body, and increase the mass productivity of the throttle body. . In addition, since the intake device has versatility as described above, not only the degree of freedom of layout can be increased, but also mass production can be improved and cost can be reduced.

Moreover, the throttle sensor, intake air temperature sensor, and boost negative pressure sensor are arranged along the intake passage axis from the upstream side of the intake passage in the order of the intake air temperature sensor, throttle sensor, and boost negative pressure sensor. The device block can be made compact.

  In addition, a communication groove is formed on the joint surface that communicates with the intake passage downstream of the throttle valve and faces the sensing portion of the boost negative pressure sensor. This communication groove can be formed on the device block joint surface by die cutting. It is very easy to manufacture.

  Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

  1 is a longitudinal sectional side view of an essential part of a motorcycle engine equipped with an intake device according to the present invention, FIG. 2 is a partially cutaway side view of the intake device of the engine, and FIG. 3 is a sectional view taken along line 3-3 of FIG. 4 is a sectional view taken along line 4-4 in FIG. 3, FIG. 5 is a sectional view taken along line 5-5 in FIG. 4, FIG. 6 is a sectional view taken along line 6-6 in FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7, and FIG. 9 is a side view of the bypass valve taken along arrow 9 in FIG.

  First, in FIG. 1, the symbol E indicates an engine mounted on the motorcycle body, and an intake pipe Ei connected to the cylinder Eh is given a gradient θ with the upstream side slightly upward. . A throttle body 1 having an intake passage 2 continuous in the pipe is connected to the upstream end of the intake pipe Ei. Therefore, the throttle body 1 is arranged so that, when connected to the intake pipe Ei, the intake passage 2 has a gradient θ with the upstream side slightly upward, like the intake pipe Ei. The upstream end of the intake passage 2 has a funnel shape, and an air cleaner (not shown) is connected thereto. A fuel injection valve I that injects fuel toward the intake valve is attached to the cylinder Eh.

  2 and 3, a pair of bosses 3 and 3 'having shaft holes 4 and 4' perpendicular to the axis of the intake passage 2 are formed on both sides of the intermediate portion of the throttle body 1, respectively. A butterfly throttle valve 5 that opens and closes the intake passage 2 is fixed to a valve shaft 6 that is rotatably supported by 4 and 4 '. A throttle drum 7 is fixed to one end of the valve shaft 6 for connecting an operation wire 9 connected to a throttle operation member (not shown). A rotor 8 a of a throttle sensor 8 that detects the opening degree of the throttle valve 5 is fixed to the other end of the valve shaft 6.

On one side of the throttle body 1, a housing 10 having a bottom surface 1a close to the intake passage 2 and parallel to the axis thereof is integrally formed. The other boss 3 ′ projects on the bottom surface 1 a of the housing 10, and the shaft hole 4 ′ and the bottom surface 1 a of the boss 3 ′ are disposed so as to be orthogonal to each other. The bottom surface 1a of the housing 10 is a flat mounting surface, and the joining surface 11a of the device block 11 accommodated in the housing 10 is overlaid on the mounting surface 1a. It is fixed to. Further, a lid plate 13 that hermetically closes the open surface of the housing 10 is secured by bolts 14.

  The device block 11 is formed with a first housing hole 37 for housing the other boss 3 ′ and the rotor 8 a, and a pickup coil 8 b is mounted on the inner wall of the first housing hole 37. The pickup coil 8b constitutes a throttle sensor 8 that electrically detects the opening degree of the throttle valve 5 in cooperation with the rotor 8a.

  As shown in FIGS. 2 to 6, a bypass path 15 is formed from the throttle body 1 to the device block 11. The bypass passage 15 includes a bypass inlet hole 20 (see FIGS. 4 and 5) formed in the throttle body 1 so as to communicate between the intake passage 2 and the mounting surface 1a upstream of the throttle valve 5. A bypass outlet hole 21 (see FIGS. 4 and 6) drilled in the throttle body 1 so as to communicate between the intake passage 2 and the mounting surface 1a downstream of the valve 5 and a joint surface 11a of the device block 11 An upstream groove portion 16 that is formed and connected to the bypass inlet hole 20 at one end, a downstream groove portion 17 that is also formed on the joint surface 11a of the device block 11 and that has one end connected to the bypass outlet hole 21, and a groove bottom at the downstream end of the upstream groove portion 16 The valve chamber inlet hole 23 opened to the bottom, the valve chamber outlet hole 24 opened to the groove bottom at the upstream end of the downstream groove portion 17, and the valve chamber inlet hole 23 and the valve chamber outlet hole 24 communicated with each other. In order composed of a valve chamber 22 in the cylinder-shaped valve guide hole 19 formed in the throttle body 1. Thus, the bypass 15 is connected to the intake passage 2 so as to bypass the throttle valve 5.

At that time, the bypass inlet bore 20, bypass outlet aperture 21及beauty before Kijikuana 4, 4 ', so that can be processed at once these multi-axis drilling machine, they are arranged parallel to one another. As shown in FIG. 4, the valve chamber outlet hole 24 is disposed above the valve chamber inlet hole 23 and offset toward the bypass inlet hole 20. The cylindrical valve guide hole 19 is parallel to the intake passage 2 and close to the upstream groove portion 16 and the downstream groove portion 17, and the valve chamber 22 is wrapped with both the valve chamber inlet hole 23 and the valve chamber outlet hole 24. To be arranged. Thus, since the valve guide hole 19 is arranged in parallel with the intake passage 2, the valve body 22 is located on the lower side when the throttle body 1 is connected to the intake pipe Ei, and the valve guide hole 19 is slightly the same as the intake passage 2. A gradient θ (see FIG. 2) is added.

  As shown in FIGS. 7 to 8, a piston-type bypass valve 25 is slidably fitted in the valve guide hole 19, and the valve chamber 22 is defined in the valve guide hole 19 by the tip of the valve 25. Is done. In order to prevent the bypass valve 25 from rotating, a key 42 integrally protruding from the inner peripheral surface of the valve guide hole 19 is engaged with the key groove 41 on the outer periphery thereof.

  The bypass valve 25 is provided with a recess 25 a that opens at the end surface on the valve chamber 22 side and forms a part of the valve chamber 22, and a measurement notch groove 26 that communicates the recess 25 a with the valve chamber outlet hole 24. In the low opening range of the bypass valve 25, the opening area of the notch groove 26 to the valve chamber outlet hole 24 is controlled to finely adjust the bypass intake amount. In the high opening range, the bypass valve 25 The opening area of the valve chamber outlet hole 24 to the valve chamber 22 is controlled at the end face, and the bypass intake air amount is relatively greatly adjusted.

  A step motor 28 is disposed coaxially with the valve 25 above the bypass valve 25 along the gradient θ (see FIG. 2), and a rotor 28 a of the step motor 28 is connected to the bypass valve 25 via a screw mechanism 27. Connected to That is, an operating member 32 having a screw hole 31 is non-rotatably fitted and attached to the central portion of the bypass valve 25, and a screw shaft 30 integrally coupled to the screw hole 31 of the operating member 32 and the rotor 28a. Are screwed together. The stator 28 b of the step motor 28 is housed and fixed in a second housing hole 38 that is continuous with the valve guide hole 19 of the device block 11.

  One end of the actuating member 32 is formed with an enormous portion 32a that abuts against the ceiling surface of the recess 25a of the bypass valve 25, and a clip 35 is engaged with the other end, and the clip 35, the bypass valve 25, In between, the coil spring 45 which urges the bypass valve 25 in the contact direction with the shoulder portion 32a is contracted. In this way, the operating member 32 is integrally connected to the bypass valve 25.

4 to 6 again, a sealing groove 46 surrounding the upstream groove portion 16 and the downstream groove portion 17 is formed on the joint surface 11a of the device block 11, and the joint surface 11a is connected to the throttle body 1 in the seal groove 46. A seal member 47 that is in close contact with the attachment surface 1a is attached when the attachment surface 1a is overlaid. Thus, the open surfaces of the grooves 16 and 17 are hermetically closed by the flat mounting surface 1a.

  Further, third and fourth accommodation holes 39 and 40 are opened on the outer surface of the device block 11 opposite to the joint surface 11a, and the fourth accommodation hole 40 is connected to the communication groove 50 and the throttle of the device block 11. It communicates with the downstream side of the intake passage 2 via the orifice 49 of the body 1. An intake air temperature sensor 34 for attaching the sensing portion 34a to the upstream groove portion 16 is mounted in the third housing hole 39, and a boost negative pressure sensor for causing the sensing portion 33a to face the communication groove 50 in the fourth housing hole 40. 33 is mounted.

  The throttle valve opening θth, the boost negative pressure Pb and the intake air temperature Ta detected by the throttle sensor 8, the boost negative pressure sensor 33 and the intake air temperature sensor 34, respectively, and the engine temperature Te detected by an engine coolant temperature sensor (not shown). Such information regarding engine operating conditions is input to the electronic control unit 36 connected to the step motor 28.

  Thus, the device block assembly 43 is configured by attaching the bypass valve 25, the step motor 28, the pickup coil 8b, the boost negative pressure sensor 23, and the intake air temperature sensor 34 to the device block 11.

  Next, the operation of this embodiment will be described.

  When the throttle valve 5 is fully closed, the electronic control unit 36 is based on the information about the engine operating conditions such as the throttle valve opening θth, the boost negative pressure Pb, the intake air temperature Ta, and the engine temperature Te that are input as described above. In order to obtain the optimum opening of the bypass valve 25 corresponding to the engine operating conditions such as engine start, fast idling, normal idling, engine braking, etc., the energization amount to the step motor 28 is calculated and the energization is performed. And the rotor 28a is rotated forward or backward. When the rotor 28a rotates or reversely rotates, the rotation is transmitted as an axial displacement to the piston-type bypass valve 25 while being decelerated by the screw mechanism 27, so that the opening degree of the bypass valve 25 can be finely adjusted.

  Thus, when the bypass valve 25 occupies a high opening position close to the step motor 28, the end face of the bypass valve 25 faces the valve chamber outlet hole 24. Therefore, the amount of intake air drawn into the engine through the bypass passage 15 Is controlled in a relatively large amount by the opening area to the valve chamber 22 to the valve chamber outlet hole 24, and can correspond to engine start and fast idling operation. When the bypass valve 25 occupies a low opening position near the valve chamber 22, the notch groove 26 of the bypass valve 25 faces the valve chamber outlet hole 24. The opening area to the valve chamber outlet hole 24 is controlled in a relatively small amount and finely, and can cope with normal idling operation and engine braking of the engine.

  If the throttle valve 5 is opened, an amount of intake air corresponding to the opening degree is supplied to the engine through the intake passage 2, and the engine moves to the output operation range.

  In such an intake device, a bypass valve 25, a step motor 28, a pickup coil 8b, a boost negative pressure sensor 23, and an intake air temperature sensor 34 are attached to a device block 11 that is detachably attached to a housing 10 integrated with the throttle body 1. Thus, since the device block assembly 43 is configured, the processing on the throttle body 1 is reduced, and the device block assembly 43 can be manufactured in parallel with the throttle body 1, thereby improving productivity. Can do. In addition, by removing the device block 11 from the throttle body 1, maintenance of the bypass path 15, the bypass valve 25, the throttle sensor 8 and the like can be easily performed. In addition, by changing the specifications of the bypass valve 25, the step motor 28, and the various sensors 8, 33, 34 in the device block 11, an intake device for an engine having different specifications can be easily provided while using the same throttle body 1. Therefore, the mass productivity of the throttle body 1 can be improved. In addition, since the intake device has versatility as described above, not only the degree of freedom of layout can be increased, but also mass production can be improved and cost can be reduced.

  Further, the upstream groove portion 16, the downstream groove portion 17, the valve chamber inlet hole 23 and the valve chamber outlet hole 24 constituting the main part of the bypass passage 15 can be formed at once at the joint surface 11 a of the device block 11, Since the valve guide hole 19 that communicates between the valve chamber inlet hole 23 and the valve chamber outlet hole 24 is arranged in parallel with the joint surface 11a of the device block 11, the upstream groove portion 16 is very easy to manufacture. In addition, the downstream groove portion 17 and the valve guide hole 19 can be arranged close to each other to form a relatively thin device block. Therefore, the protrusion of the device block 11 from the throttle body 1 can be reduced, and the entire intake device can be reduced. Compactness can be achieved.

  Further, when the throttle body 1 is attached to the engine E of the motorcycle, the bypass valve 25 and the step motor 28 connected via the screw mechanism 27 have only a slight gradient θ close to the horizontal. Even if the vertical vibration is received, the vertical vibration does not act on the connecting portion of the bypass valve 25 and the step motor 28, that is, the screw mechanism 27, and wear due to the vibration of the mechanism 27 is avoided. The performance can be stabilized.

  Moreover, since the gradient θ applied to the bypass valve 25 and the step motor 28 makes the step motor 28 upward, fluid foreign substances such as oil and moisture in blow-by gas and EGR gas are attracted to the intake passage 2 during engine operation. Even if the foreign matter enters the valve chamber 22 of the bypass passage 15, the foreign matter does not rise to the step motor 28 side, and therefore the step motor 28 is prevented from causing malfunction due to freezing or accumulation of foreign matter. be able to.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention.

The principal part vertical side view of the engine for motorcycles provided with the intake device concerning the present invention. The partially broken side view of the intake device of the said engine. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. FIG. 4 is a sectional view taken along line 4-4 of FIG. FIG. 5 is a sectional view taken along line 5-5 of FIG. FIG. 6 is a sectional view taken along line 6-6 in FIG. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 3. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. FIG. 9 is a side view of the bypass valve taken along arrow 9 in FIG. 8.

Explanation of symbols

E ... Engine 1 ... Throttle body 1a ... Mounting surface 2 ... Intake passage 5 ... Throttle valve 8 ... Throttle sensor 11 ... · Device block 11a · · · Joint surface 33 · · · Boost negative pressure sensor 33a · · · Sensing unit 34 · · · Intake air temperature sensor
40... Accommodation hole
46... Seal groove
47 ... Seal member 50 ... Communication groove

Claims (1)

A throttle body (1) having an intake passage (2), and a throttle valve (5) attached to a valve shaft (6) rotatably supported by the throttle body (1) to open and close the intake passage (2); , A throttle sensor (8) for detecting the rotation angle of the valve shaft (6) as the opening of the throttle valve (5), an intake air temperature sensor (34) for detecting the intake air temperature, and an intake air downstream from the throttle valve (5) In an engine intake device comprising a boost negative pressure sensor (33) for detecting boost negative pressure in the road (2),
A joining surface (11a) of the device block (11) is detachably joined to a flat mounting surface (1a) formed in parallel to the axis of the intake passage (2) to the throttle body (1). the (11), a throttle sensor (8), is attached to the intake air temperature sensor (34) and the boost negative pressure sensor (33), upstream of the sensor (8,33,34) of an intake passage (2) To the intake air temperature sensor (34), throttle sensor (8), boost negative pressure sensor (33) in this order along the axis of the intake passage (2) , and the joint surface (11a) of the device block (11) A housing hole (40) for housing the boost negative pressure sensor (33) is opened on the outer surface on the opposite side, and the intake surface (2) downstream of the throttle valve (5) is formed on the joint surface (11a). ) The boost sensing portion of the negative pressure sensor (33) through a communication groove for exposing the (33a) (50), forms a sealing groove (46) surrounding the communicating groove (50), the sealing groove (46) An air intake device for an engine , wherein a seal member (47) is attached to the air intake device.

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