EP1995435A1

EP1995435A1 - Engine control device and two-wheeled vehicle

Info

Publication number: EP1995435A1
Application number: EP07737894A
Authority: EP
Inventors: Osamu Miura; Daisuke Hamasaki
Original assignee: Mikuni Corp
Current assignee: Mikuni Corp
Priority date: 2006-03-07
Filing date: 2007-03-06
Publication date: 2008-11-26
Also published as: EP1995435A4; WO2007105546A1; CN101395360B; JP2007239560A; CN101395360A

Abstract

An engine control device having a throttle body (1) provided with an air intake path, a sensor unit case (3) prepared in a process separate from that for the throttle body (1) and receiving a sensor unit, an ISC unit case (2) for receiving an ISC stepper motor (23) and ISC control valves (25-1, 25-2) that are prepared in processes separate from that for the throttle body (1), that are separate bodies from the sensor unit case (3), and that control the amount of air in idle speed, and screws (13, 14, 15, 18) for individually attaching the sensor unit case (3) and the ISC unit case (2) to the throttle body (1).

Description

[Technical Field]

The present invention relates to an engine control device and to a moving body, particularly a two-wheeled vehicle that comprises the engine control device.

[Background Art]

Conventionally, a device has been disclosed (for example refer to patent document 1) in which due to miniaturization (space saving design) and other reasons, sensors (throttle opening sensor, pressure sensor, temperature sensor, coolant temperature sensor) are arranged such that they are integrated in the throttle body, with the output signals from a plurality of sensors being output from an aggregate output terminal.
Moreover, in other related art a device is disclosed (for example, refer to patent document 2) in which the device is housed in a casing that is formed in the throttle sleeve as a pre-assembled and pre-inspected unit comprising an electronic control device, throttle mechanism, throttle adjustment motor, and purge valve air volume sensor. Furthermore, a device is disclosed (for example, patent document 2) in which a sensor unit, and a so-called ISC (Idle Speed Control) unit that controls the amount air during idling are integrated.

Patent document 1: Japanese patent application No. H9-250374
Patent document 2: Japanese patent application No. H9-508954
Patent document 3: Japanese patent application No. 2002-349397

[Summary of the Invention]

[Problems Solved by the Invention]

However, in the related art described above, when the throttle body and ECU case are formed such that they integrated together, even though precision is not particularly required for the ECU case, it is necessary that a suitable material be used for the throttle body in order to maintain the fully closed precision of the throttle, and there are cases in which the overall body becomes very expensive. Particularly in the case in which the device is applied to a two-wheeled vehicle, the aperture of the throttle body is determined by the required amount of air intake, so many variations having different aperture sizes must be set. Therefore, the cost further increases due to reasons such as it being impossible to perform mass production.
Moreover, when each case is integrally formed in the throttle body, the construction of the mold becomes complicated and it become difficult to form a plurality of devices at one time, so the cost increases. In addition, when each of the cases are integrated together, it is necessary that the material have a uniform thickness, so there is a problem in that a deeper amount of material must be removed for each case and a large amount of material is required in order to fill the removed spaces with resin.
Furthermore, when the throttle body is integrated with each of the cases, the location for placing an aggregate input/output terminal for inputting or outputting various kinds of information to or from the sensors of each of the cases, and for supplying power is limited. In other words, the aggregate input/output terminal must be located on the outside of the integrated throttle body and case terminals themselves, and therefore, space for the aggregate input/output terminal itself and space for the wiring that is connected to the aggregate input/output terminal must be maintained on the outside of the integrated throttle body and case terminals themselves, so there is a problem in that the space occupied by the engine control device increases by that amount, and there is a decrease in the freedom for installing other devices. In the case of a two-wheeled vehicle, when the restrictions on the width of the vehicle frame and the damage that may occur when the vehicle tips over are taken into consideration, the installation location of the aggregate input/output terminal becomes an important problem
In the case where the sensor unit and ISC unit are integrated as in the related art, the overall unit becomes large due to the handling of the bypass air path. In addition, the shape of the O-ring or the like used for sealing the path becomes complex, thus the cost of parts increases and there is a decrease in the assembly efficiency, resulting in an overall increase in cost of the device.
In the case of a two-wheeled vehicle, and more particularly in the case of a two-wheeled vehicle in which a compact engine having low emissions is mounted, the amount of space for housing the engine, including the engine control device, is limited, so an efficient, space saving design of an overall engine control device, including the position of the wires for driving the throttle lever, and wiring for the power supply and output signals, is required.
In order to solve the problems described above, it is the object of the present invention to provide a compact and low-cost engine control device, and a moving body (particularly, a two-wheeled vehicle) that comprises that engine control device.

[Means for Solving the Problems]

In order to solve the aforementioned problems, the engine control device of the present invention comprises: a throttle body having an air-intake path; a sensor unit case that is formed in a process separate from the throttle body, and that houses a sensor unit comprising at least one sensor from among a TPS (Throttle Position Sensor) that detects the position of a valve that opens and closes the air-intake path, an air-intake pressure sensor that detects the pressure inside the air-intake path, and an air-intake temperature sensor that detects the temperature of the air-intake path; an ISC unit case that is formed in a process separate from the throttle body, that is separate from the sensor unit case, and that houses an ISC (Idle Speed Control) unit that controls the amount of air during idling operation; and installation means for attaching the sensor unit case and the ISC unit case to the throttle body.
Moreover, in the engine control device of the present invention described above, at least one of the sensor unit case and the ISC unit case is made of a material that is different than that of the throttle body.
Furthermore, in the engine control device of the present invention described above, the throttle body comprises a throttle lever that is located on one end of a throttle shaft and that rotates that throttle shaft; and at least one of the sensor unit case and the ISC unit case is attached on the side of the other end of the throttle shaft.
In the engine control device of the present invention described above, a bypass air path is formed in the throttle body.
In addition, in the engine control device of the present invention described above, the ISC unit comprises an ISC control valve that controls the opening and closing of the bypass air path, and drive means for driving that ISC control valve; and the ISC control valve is located further on the upper side than the throttle shaft when the engine control device is mounted in a moving body, where by moving in a two dimensional direction, the ISC control valve controls the opening and closing of said bypass air path.
Moreover, in the engine control device of the present invention described above, the drive means comprises a stepping motor and a rotating shaft that transmits the rotation drive of that stepping motor; and the ISC control valve comprises a convex section that comes in contact with a specified position of the throttle body, and a spiral-shaped groove that fits with a spiral-shaped groove that is formed in the rotation shaft when rotated; such that when the rotating shaft rotates forward or in reverse, the specified position on the throttle body comes in contact with the convex section of the ISC control valve to restrain the rotation of the ISC control valve, and by maintaining the fit between the spiral-shaped groove with the spiral-shaped groove that is formed in the ISC control valve, the ISC control valve moves in either lengthwise direction of the rotating shaft.
In addition, in the engine control device of the present invention described above, the ISC control valve is tapered on the tip end in the lengthwise direction of the rotating shaft and controls the opening and closing of the bypass air path by moving in that lengthwise direction in order to adjust the surface area of the space that exists between the ISC control valve and the bypass air path.
Furthermore, in the engine control device of the present invention described above, the drive means controls the opening and closing of the bypass air path by moving the ISC control valve in a direction that is parallel with the lengthwise direction of the throttle bore when viewed from above when the engine control device is mounted in a moving body.
In the engine control device of the present invention described above, the drive means controls the opening and closing of the bypass air path by moving the ISC control valve in a direction orthogonal to the lengthwise direction of the throttle bore when viewed from above when the engine control device is mounted in a moving body.
Moreover, in the engine control device of the present invention described above, the bypass air path has at least an upstream path that connects to the air-intake side of the throttle bore; and the drive means controls the opening and closing of the bypass air path by moving the ISC control valve in a direction orthogonal to the lengthwise direction of the upstream path.
Furthermore, in the engine control device of the present invention described above, the bypass air path has at least an upstream side path that connects to the air-intake side of the throttle bore, and a downstream side path that connects to the exhaust side of the throttle bore; with the bypass air path being continuous and turning at least three times from the upstream side path to the downstream side path.
The engine control device of the present invention comprises: a throttle body; a valve that opens or closes an air-intake path that is formed in the throttle body; a throttle shaft that is mounted in the valve; a rotation mechanism that rotates the throttle shaft; a Throttle Position Sensor (TPS) that detects the position of the valve that opens or closes the air-intake path; an air-intake pressure sensor that detects the pressure inside said air-intake path; an air-intake temperature sensor that detects the temperature of the air-intake path; and an ISC that controls the amount of air during idling; wherein the TPS, the air-intake pressure sensor, the air-intake temperature sensor and ISC are located on the opposite side of the air-intake path from the drive mechanism.
In the engine control device of the present invention described above, the drive mechanism is an actuator that is rotated by the driving force from a drive source.
Moreover, in the engine control device of the present invention described above, the drive mechanism is driven by a lever that is operated by a wire that is linked to an axle.
The engine control device of the present invention comprises: a throttle body having an air-intake path; a sensor unit case that is formed in a process separate from the throttle body, and that houses a sensor unit comprising at least one sensor from among a TPS (Throttle Position Sensor) that detects the position of a valve that opens and closes said air-intake path, an air-intake pressure sensor that detects the pressure inside the air-intake path, and an air-intake temperature sensor that detects the temperature of the air-intake path; and installation means for attaching the sensor unit case and the ISC unit case to the throttle body; wherein the sensor unit case has an aggregate cover that houses an aggregate input terminal; and the input section of the aggregate input terminal is located on the upstream side of the throttle body.
The two-wheeled vehicle of the present comprises the engine control device of the invention described above.

[Advantages of the Invention]

As was explained above, with the present invention, by individually installing a sensor unit case and an ISC unit case, which is formed separately from the sensor unit case, in a throttle body, it is possible to make the engine control device more compact, as well as simplify adjustment during installation, and in so doing, it is possible to obtain a compact and low-cost engine control device and a moving body (particularly a two-wheeled vehicle) that comprises the engine control device.

[Brief Explanation of the Drawings]

FIG 1 is a front view showing the engine control device of an embodiment of the present invention.
FIG. 2 is a top view showing the engine control device of an embodiment of the present invention.
FIG. 3 is a right side view showing the engine control device of an embodiment of the present invention.
FIG 4 is a left side view showing the engine control device of an embodiment of the present invention.
FIG. 5 is a cross-sectional view of section A-A in FIG. 1.
FIG. 6-1 is a cross-sectional view of section B-B in FIG. 4.
FIG. 6-2 is a cross-sectional view of section B-B in FIG. 4.
FIG. 6-3 is a view of the ISC control valve as seen from the C direction.
FIG. 7 is a front view of the throttle body.
FIG. 8 is a right side view of the throttle body.
FIG. 9 is an exploded pictorial view showing the engine control device of an embodiment of the present invention.
FIG. 10 is an explanatory drawing showing the bypass air path.
FIG. 11 is an explanatory drawing showing the bypass air path.
FIG. 12 is an explanatory drawing showing the bypass air path.
FIG. 13 is an explanatory drawing (pictorial drawing) showing an example of different construction of the sensor unit case.
FIG. 14 is an explanatory drawing (pictorial drawing) showing an example of different construction of the sensor unit case.

[Explanation of the Reference Numbers]

1 Throttle body
2 ISC unit case
3, 101 Sensor unit case
4 Aggregate input/output terminal cover
5 Aggregate input/output terminal
6 Throttle lever
7 Return spring
8 Throttle valve
9 Throttle screw
10 Bracket
11 Adjustment screw
12 Nut
13 Screws (for attaching the ISC unit case)
14 Screws (for attaching the sensor unit case)
15 Screws (for attaching the ISC unit case)
16 Screws (for attaching the bracket)
17 Screws (for attaching the bracket)
18 Screws (for attaching the sensor unit case)
19 Throttle shaft
20, 103 Air-intake temperature sensor
21 Bypass air hole
22 Bypass air path (upstream side)
23 ISC stepper motor
24 Rotation prevention unit
25 (25-1 to 25-4) ISC control valves
26 Bypass air path (middle)
27 Screw (for attaching the ISC stepper motor)
28 Rotation shaft
29, 104 TPS
30 O-ring
31 Washer
32 Spring washer (for the throttle shaft)
33 Nut (for the throttle shaft)
34 Packing
35 Seal
36 Ring
50 Air-intake pressure sensor hole
51 Air-intake temperature sensor hole
53 Screw hole (for attaching the ISC unit case)
54, 106 screw holes (for attaching the sensor unit case)
55 Screw hole (for attaching the ISC unit case)
57 Screw hole (for attaching the ISC stepper motor)
58, 107 Screw holes (for attaching the sensor unit case)
60 Bypass air path (middle)
61 Bypass air path (downstream side)
102 Aggregate input/output terminal cover
105 Air-intake pressure sensor
106, 107 Screw holes (for attaching the sensor unit case)

[Best Mode for Carrying Out the Invention]

The preferred embodiments of an engine control device and a moving body (particularly, a two-wheeled vehicle) that comprises that engine control device of the present invention will be explained with reference to the supplied drawings. This invention is not limited to the embodiments described below, and various variations are possible.

(Construction of the Engine control device)

First, the construction of an engine control device of an embodiment of the present invention will be explained. FIG. 1 is a front view showing the engine control device of an embodiment of the present invention; Fig. 2 is a top view showing the engine control device of an embodiment of the present invention; FIG. 3 is a right side view showing the engine control device of an embodiment of the present invention; and FIG. 4 is a left side view showing the engine control device of an embodiment of the present invention.
In FIG. 1 to FIG. 4, the engine control device is for a two-wheeled vehicle and particularly a compact engine having little exhaust (for example, a 50 to 250cc engine), and comprises: a throttle body 1; an ISC unit case 2 that houses an ISC unit (described in detail later) that controls the amount of air during idling; and a sensor unit case 3 that houses a sensor unit (described in detail later). The sensor unit case 3 is made in a separate process from the throttle body 1.
Moreover, the ISC unit case 2 is also made in a separate process from the throttle body 1. Furthermore, the ISC unit case 2 is attached to the throttle body 1 as a separate body from the sensor unit case 3.
It is preferable that the throttle body 1 and ISC unit case 2 be made of different materials; for example, the throttle body 1 can be made of metal, and more specifically, formed by aluminum die cast, and the ISC unit case 2 can be made of plastic or resin. Similarly, it is preferable that the throttle body 1 and the sensor unit case 3 be made of different materials; for example, the throttle body 1 can be made of metal, and more specifically, formed by aluminum die cast, and the sensor unit case 3 can be made of plastic or resin.
The ISC unit case 2 and sensor unit case 3 can be made of the same material or can be made of different material.
Depending on the material used for the ISC unit case 2 and sensor unit case 3, it is possible to use cases having excellent heat resistance, and thus protect the ISC unit that is housed in the ISC unit case 2, and the sensor unit that is housed in the sensor unit case 3 from heat.
Together with making the throttle body 1 and ISC unit case separate in this way, the throttle body 1 and the sensor unit case 3 are also made to be separate, and by producing the mechanical elements and electrical elements separately, it is possible to keep production costs low, and improve performance after assembly. Furthermore, by making the ISC unit case 2 separate from the sensor unit case 3, and by installing them separately in the throttle body 1, it is possible to more easily perform the work of adjustment during installation than when both are integrated together and installed.
Moreover, the throttle body 1 is a butterfly valve type, where the throttle lever 6 comprises a return spring 7, throttle valve 8, a throttle screw 9 that attaches the throttle valve 8 to a throttle shaft 19 (refer to FIG. 5, FIG. 6-1, FIG. 6-2, and FIG. 9 that will be described later), a bracket 10, an adjustment screw 11, and a nut 12 for the adjustment screw 11. In addition, the bracket 10 guides a wire for rotating and driving the throttle lever 6 and is attached to the throttle body 1 by screws 16 and 17.
The ISC unit case 2 comprises an aggregate input/output terminal cover 4 that is formed into a single body with the ISC unit case 2 and that houses an aggregate input/output terminal 5. The input section of the aggregate input/output terminal cover 4 faces toward the upstream side of the throttle body 1. This makes it possible to more efficiently arrange the wiring. In addition, as shown in FIG. 4, the ISC unit case 2 is directly attached to the throttle body 1 by screws 13 and 15 for attaching the ISC unit case 2. Similarly, the sensor unit case 3 is directly attached to the throttle body 1 by screws 14 and 18 for attaching the sensor unit case 3.
In this way, the throttle body 1 comprises a throttle lever 6 that is located on one end of the throttle shaft 19, or in other words the end on the right side in FIG. 1, and that rotates the throttle shaft 19, while at the same time, the ISC unit case 2 and sensor unit case 3 are installed on the other end of the throttle shaft 19, or in other words, the end on the left side in FIG. 1. By doing so, it is possible to place both the ISC unit case 2 and sensor unit case 3 or just either one of the cases in a location that does not hinder rotation when the throttle shaft 19 is rotating, and to further conserve space.
As a result, the TPS 29, air-intake pressure sensor, air-intake temperature sensor 20 and ISC unit 25 are located on the opposite side of the throttle bore, which is the air-intake path, from the throttle lever 6, which is the rotation mechanism.
The throttle lever 6, which is the rotation mechanism, can be an actuator that is rotated by a driving force from a drive source that is not shown in the figures. Moreover, the throttle lever 6 can be driven by a lever that is operated by a wire not shown in the figures that is linked to the axle.
FIG. 5 is a cross-sectional view of the section A-A in FIG. 1. In FIG. 5, the right side of the throttle bore is the upstream side, and from the right side to the left side is the air-intake direction. In FIG. 5, reference number 8 is a throttle valve, and in the figure it is nearly in the completely closed state. This throttle valve 8 rotates in the counterclockwise direction of FIG. 5 as the throttle shaft 19 rotates, allowing air intake. Moreover, in FIG. 5, reference number 21 is a bypass air hole for maintaining air intake during idling when the throttle valve 8 is completely closed. A bypass air path 22 that is formed in this way by the bypass air hole 21 is formed on both sides of the throttle valve 8 on the upstream side and downstream side of the intake so that air goes through the throttle bore (see FIG. 12). Particularly, it is preferred that this device, which is the engine control device, be located further on the upstream side than the throttle shaft 19 when mounted in a moving body (especially a two-wheeled vehicle).

(Construction of the ISC Unit)

FIG. 6-1 and FIG. 6-2 are cross-sectional views of section B-B in FIG. 4. FIG. 6-3 is a view of the ISC control valve 25 as seen in the direction C (from left side in FIG. 6-1). In FIG. 6-1 and FIG. 6-2, reference number 23 is an ISC stepper motor, and the ISC unit is housed inside the ISC unit case 2. The ISC unit comprises: an ISC control valve 25, and an ISC stepper motor 23 that drives that ISC control valve 25. The reference number 26 is the bypass air path, and 27 is a screw for attaching the stepper motor 23, such that the ISC stepper motor 23 is attached to the throttle body 1 by this screw 27. By performing drive control, the ISC stepper motor 23 can rotate the rotating shaft 28 forward and reverse. A spiral shaped groove is formed on the surface of the rotating shaft 28.
The ISC control valve 25 comprises a tip-end section 25-1 and a rear-end section 25-2. The tip-end section 25-1 is shaped such that it has a tapered section that tapers toward the convex section of the tip end (triangular cone shape). As shown in FIG. 6-3 and FIG. 9, the rear-end section 25-2 comprises a convex section around the circumference that has a longer diameter than the bottom section of the triangular cone shape of the tip-end section 25-1. As shown in FIG. 6-1 and FIG. 6-2 a spring may be placed in the space where the ISC control valve 25 moves. By using a spring, it is possible to more reliably open and close the ISC control valve 25.
Moreover, as shown in FIG. 6-3, a spiral shaped fitting hole 25-4, which is formed with a screw shaped groove that is similar to the spiral shaped groove of the rotating shaft 28, is provided on the inside of the ISC control valve 25 so that it fits with the spiral shaped groove of the rotating shaft 28. Furthermore, as shown in FIG. 6-3 and FIG. 9, there are convex sections 25-3 around the outer surface of the ISC control valve 25. These convex sections 25-3 come in contact with a rotation-prevention unit 24 that is shown in FIG. 8, and prevent the ISC control valve 25 from rotating together with the rotation of the rotating shaft 28, even though the rotating shaft 28 may rotate.
In other words, The ISC stepper motor 23 is such that with the spiral shaped groove section on the inside of the ISC control valve 25 fitted with the spiral shaped groove section of the rotating shaft 28, and with the ISC control valve 25 inserted into a insertion hole that is formed in the throttle body 1, the ISC stepper motor 23 is attached to the throttle body 1 with the screw 27. When doing this, the rear end section of the ISC control valve 25 comes in contact with the rotation prevention unit 24 that is provided in the throttle body 1 (see, FIG. 6-1, FIG, 6-2, and FIG. 8) so that ISC control valve 25 does not rotate.
FIG. 8 is a left side view of the throttle body 1. In FIG. 8, the reference number 57 are screw holes for attaching the ISC stepper motor 23, with two holes 57 being provided around the circumference of the insertion hole in which the ISC control valve 25 is inserted. In addition, the rotation prevention unit 24 for preventing the ISC control valve 25 from rotating is also located in the insertion hole in which the ISC control valve 25 is inserted. Both are located in the throttle body 1.
The rotation prevention unit 24 is a groove having an oval shaped cross section as shown in FIG. 8, where the section having the short diameter is a little larger than the rear end section 25-2, and is less than a diameter that takes into consideration the convex sections 25-3. Therefore, when the ISC control valve 25 is inserted into the insertion hole in the throttle body 1, the rear end section 25-2 fits inside this oval section, however, since there are the convex sections 25-3, the rear end section 25-2 cannot rotate while inside the oval section. This kind of construction prevents (restrains) the ISC control valve 25 from rotating.
In this kind of state, when the spiral shaped groove of the rotating shaft 28 fits with the spiral shaped groove of the ISC control valve 25 (fitting hole 25-4) and the rotating shaft 28 is rotated in a specified direction, the ISC control valve 25 is prevented from rotating, so by maintaining the fit between the spiral shaped groove of the rotating shaft 28 and the spiral shaped groove formed in the ISC control valve 25, it is possible to move the ISC control valve 25 along the lengthwise direction of the rotating shaft 28 in the direction going toward the ISC stepper motor 23, and when the rotating shaft 28 is rotated in the direction opposite that specified direction, it is possible to move the ISC control valve 25 along the lengthwise direction of the rotating shaft 28 in the direction going away from the ISC stepper motor 23.
In this way, the ISC control valve 25 is positioned such that it can moved in the lengthwise direction of the rotating shaft 28, however it does not rotate due to the rotation prevention unit 24, so when the rotating shaft 28 rotates in a specified direction, the ISC control valve 25 moves along the lengthwise direction of the rotating shaft 28 in the direction going toward the ISC stepper motor 23, and when the rotating shaft 28 rotates in the direction opposite that specified direction, the ISC control valve 25 moves along the lengthwise direction of the rotating shaft 28 in the direction going away from the ISC stepper motor 23. When the ISC control valve 25 moves in the direction going away from the ISC stepper motor 23, the taper section of the ISC control valve 25 will come in contact with the bypass air path at a specified position. This state is shown in FIG. 6-2. In this state, the bypass air path is blocked, and thus the flow of air is blocked.
Moreover, when the rotating shaft 28 rotates in the aforementioned specified direction, the ISC control valve 25 moves in the direction toward the ISC stepper motor 23. The space between the bypass air path and the tapered section of the convex section of the ISC control valve 25 opens according to the amount of movement. By adjusting the surface area of the space that occurs between the ISC control valve 25 and the bypass air path in this way, it is possible to control the opening and closing of the bypass air path 60 by simply controlling the rotation drive of the FISC stepper motor 23 (see FIG. 6-1). That is, it is possible to control the opening and closing of the bypass air path and amount of opening according to the direction and amount of rotation of the ISC stepper motor 23.
When the ISC control valve 25 is viewed from the top with the engine control device of the present invention being mounted in a moving body such as a two-wheeled vehicle, or in other words, in the top view of FIG. 2, driving the ISC control valve 25 in a direction that is parallel with the lengthwise direction of the throttle shaft 19 (horizontal direction in FIG. 2) controls the opening and closing of the bypass air path.
Moreover, when the ISC control valve 25 is viewed from the top with the engine control device of the present invention being mounted in a moving body such as a two-wheeled vehicle (in the top view of FIG. 2), driving the ISC control valve 25 in a direction that is orthogonal to the lengthwise direction of the throttle bore (vertical direction in FIG. 2) controls the opening and closing of the bypass air path.

(Construction of the Sensor Unit),

FIG. 7 is a front view of the throttle body 1, and FIG. 8 is a right side view of the throttle body 1. Both figures show the sate in which the ISC unit case 2 and the units inside the case are separated, and the state in which the sensor unit case 3 and each of the sensors in the case are separated (however, part of the TPS 29 is mounted to the throttle shaft 19).
In FIG. 7 and FIG. 8, reference number 29 is the TPS. In addition, in FIG. 8, reference number 50 is a hole for an air-intake pressure sensor, reference number 51 is a hole for an air-intake temperature sensor, reference numbers 53 and 55 are screw holes for attaching the ISC unit case 2, and reference numbers 54 and 58 are screw holes for attaching the sensor unit case 3. Moreover, in FIG. 1, reference number 2 is the tip end of the air-intake temperature sensor that protrudes inside the throttle bore via the hole 51 for the air-intake temperature sensor.

(Assembly of the Engine control device)

FIG. 9 is an exploded pictorial view showing the engine control device of an embodiment of the present invention. In FIG. 9 reference number 30 is an O-ring, reference number 31 is a washer, reference 32 is a spring washer for the throttle shaft 19, reference number 33 is a nut for the throttle shaft 19, reference number 34 is packing, reference number 35 is a seal, and reference number 36 is a ring.
By attaching the ISC unit case 2 to the throttle body 1 via the O-ring 30, the ISC stepper motor 23 is protected from dust and moisture. By placing a washer 31 between the ISC stepper motor 23 and ISC control valve 25, it is possible to rotate the ISC control valve 25 more smoothly.
In addition, it is possible to securely attach the throttle lever 6 to the throttle shaft 19 using the spring washer 32 for the throttle shaft 19 and the nut 33 for the throttle shaft 19. Moreover, the packing 34 and seal 35 protect the TPS 28 from dust and moisture that enters from the throttle bore. Furthermore, the ring 36 makes it possible to rotate the throttle shaft 19 more smoothly.

(Construction of the Bypass Air Path)

FIG. 10 to FIG. 12 are explanatory drawings showing the bypass air path, where FIG. 10 is a front view similar to that of FIG. 1 showing the engine control device; FIG 11 is a top view similar to that of FIG. 2 of the engine control device; and FIG. 12 is a cross-sectional view similar to that of FIG. 8 of section A-A in FIG. 10.
In FIG. 10 to FIG. 12, reference number 22 is the upstream side of the bypass air path, reference number 61 is the downstream side of the bypass air path, reference number 26 and reference number 60 are bypass air paths (intermediate bypass air paths) that connect the upstream bypass air path 22 with the downstream bypass air path 61. In FIG. 11, the intermediate bypass air paths 26 and 60 are orthogonal forming a so-called inverted L shape, and are such that they connect vertically with the upstream bypass air path 22 at the lower left, and connect with the downstream bypass air path 61 at the upper right.
The bypass air path comprises at least an upstream bypass air path 22 that connects to the air-intake side of the throttle bore, and a downstream bypass air path 61 that connects to the exhaust side of the throttle bore, such that the bypass air path turns at least three times or more from the upstream bypass air path 22 to the downstream bypass air path 61 via the intermediate bypass air paths 26, 60.
By doing this, it is possible to more easily create a hole for the bypass air path when forming the throttle body 1 using a die. In addition, by bending the path in an inverted L shape as described above, it is possible for the ISC control valve 25 to more easily adjust the amount of air flow.

(Examples of Different Construction for the Sensor Unit Case)

FIG. 13 is an explanatory drawing (pictorial view) showing an example of different construction of a sensor unit case. In FIG. 13 the sensor unit case 101 includes an aggregate input/output terminal cover 102, air-intake temperature sensor 103, TPS 104, air-intake pressure sensor 105, and screw holes (for attaching the sensor unit case) 106, 107. The screw hole 106 corresponds to the screw hole 54 shown in FIG. 8, and the screw hole 107 corresponds with the screw hole 58 shown in FIG. 8.
This sensor unit case 101 can be attached to the throttle body 1 instead of the sensor unit case 3 described above. In FIG. 13, the arrow in the C direction indicates the installation surface. Moreover, the arrow in the A direction indicates the upstream side of the throttle bore, and the arrow in the B direction indicates the downstream side of the throttle bore. One feature of this sensor unit case 101 is that the aggregate input/output terminal that is housed inside the aggregate input/output terminal cover 102 faces the upstream side of the throttle bore (in other words, the side of the arrow in the A direction).
FIG. 14 is an explanatory drawing (pictorial view) showing another example of different construction of a sensor unit case. FIG. 14 shows an example in which the sensor unit case shown in FIG. 13 is installed upside down. Depending on the orientation of the upstream side and downstream side of the throttle bore, the aggregate input/output terminal cover 102 may be arranged on the bottom as shown in FIG. 13, or the aggregate input/output terminal cover 102 may be arranged on top as shown in FIG. 14. In either case, it is preferred that the air-intake temperature sensor 103 be located further upstream than the throttle valve 8, and that the air-intake pressure sensor 105 be located further downstream than the throttle valve 8.
This example comprises a sensor unit case 101, which houses a sensor unit having at least one sensor from among a TPS that is made in a process separate from that of the throttle body 1, an air-intake pressure sensor and air-intake temperature sensor, and installation means (screw not shown in the figure) for attaching the sensor unit case 101 to the throttle body 1, where the sensor unit case 101 has an aggregate input/output terminal cover 102 that houses an aggregate input/output terminal (not shown in the figure), and the aggregate input/output terminal cover 102 is located upstream from the throttle body 1, or in other words, the input section is located such that it faces toward the upstream side of the throttle bore, so it is possible to easily run the wiring from the upstream side of the throttle bore, increasing the freedom in running the wiring, and thus it is possible to more efficiently layout the wiring.
As was explained above, the embodiments of the present invention comprise: a throttle body 1 that comprises an air-intake path; a sensor unit case 3 that houses a sensor unit that is formed in a separate process from the throttle body 1 and that comprises at least one sensor from among a TPS, air-intake pressure sensor and air-intake temperature sensor; an ISC unit case 2 that is separate from the sensor unit 3 and that is formed in a process separate from the throttle body 1, and screws 13, 14, 15, 18 as installation means for attaching the sensor unit case 3 and ISC unit case 2 to the throttle body 1.
Therefore, when taking into consideration fine adjustment during installation of each of the units, since it is possible to separately attach the sensor unit case 3 and ISC unit case 2 to the throttle body 1, assembly efficiency can be improved.
Moreover, the embodiments of the present invention comprise a throttle lever 6 on one end of the throttle shaft 19, and the sensor unit case 3 and ISC unit case 2 are attached on the side of the other end of the throttle shaft 19, so they do not hinder the rotation of the throttle lever 6, and it is possible to suppress the overall size of the engine control device by the amount that it is no longer necessary to take the bypass air path for controlling the amount of air during idling of the ISC unit around the throttle lever 6.
Furthermore, with the embodiment of this invention, the tip end 25-1 of the ISC control valve 25 is tapered in the lengthwise direction of the rotating shaft 28, and by moving the ISC valve 25 in the lengthwise direction to adjust the surface area of the space that occurs between the ISC control valve 25 and the bypass air path 60 it is possible to control the opening and closing of the bypass air path, so by controlling the rotation drive of the ISC stepper motor 23 it is possible to adjust the amount of air with high accuracy.

[Industrial Applicability]

The engine control device of the present invention is useful when applied to a moving body such as a two-wheeled vehicle that comprises an internal combustion engine, and particularly is useful when applied to an engine with a small amount of exhaust.

Claims

An engine control device comprising:
a throttle body having an air-intake path;

a sensor unit case that is formed in a process separate from said throttle body, and that houses a sensor unit comprising at least one sensor from among a TPS (Throttle Position Sensor) that detects the position of a valve that opens and closes said air-intake path, an air-intake pressure sensor that detects the pressure inside said air-intake path, and an air-intake temperature sensor that detects the temperature of said air-intake path;

an ISC unit case that is formed in a process separate from said throttle body, that is separate from said sensor unit case, and that houses an ISC (Idle Speed Control) unit that controls the amount of air during idling operation; and

installation means for attaching said sensor unit case and said ISC unit case to said throttle body.
The engine control device of claim 1 wherein at least one of said sensor unit case and said ISC unit case is made of a material that is different than that of said throttle body.
The engine control device of claim 1 wherein
said throttle body comprises a throttle lever that is located on one end of a throttle shaft and that rotates that throttle shaft; and
at least one of said sensor unit case and said ISC unit case is attached on the side of the other end of said throttle shaft.
The engine control device of claim 1 wherein a bypass air path is formed in said throttle body.
The engine control device of claim 4 wherein
said ISC unit comprises an ISC control valve that controls the opening and closing of said bypass air path, and drive means for driving that ISC control valve; and
said ISC control valve is located further on the upper side than said throttle shaft when the engine control device is mounted in a moving body, where by moving in a two dimensional direction, the ISC control valve controls the opening and closing of said bypass air path.
The engine control device of claim 5 wherein
said drive means comprises a stepping motor and a rotating shaft that transmits the rotation drive of that stepping motor; and
said ISC control valve comprises a convex section that comes in contact with a specified position of said throttle body, and a spiral-shaped groove that fits with a spiral-shaped groove that is formed in said rotation shaft when rotated; such that
when said rotating shaft rotates forward or in reverse, said specified position on said throttle body comes in contact with said convex section of said ISC control valve to restrain the rotation of the ISC control valve, and by maintaining the fit between said spiral-shaped groove with the spiral-shaped groove that is formed in the ISC control valve, the ISC control valve moves in either lengthwise direction of said rotating shaft.
The engine control device of claim 6 wherein said ISC control valve is tapered on the tip end in the lengthwise direction of said rotating shaft and controls the opening and closing of said bypass air path by moving in that lengthwise direction in order to adjust the surface area of the space that exists between the ISC control valve and said bypass air path.
The engine control device of claim 4 wherein said drive means controls the opening and closing of said bypass air path by moving said ISC control valve in a direction that is parallel with the lengthwise direction of said throttle bore when viewed from above when the engine control device is mounted in a moving body.
The engine control device of claim 4 wherein said drive means controls the opening and closing of said bypass air path by moving said ISC control valve in a direction orthogonal to the lengthwise direction of said throttle bore when viewed from above when the engine control device is mounted in a moving body.
The engine control device of claim 4 wherein
said bypass air path has at least an upstream path that connects to the air-intake side of said throttle bore; and
said drive means controls the opening and closing of said bypass air path by moving said ISC control valve in a direction orthogonal to the lengthwise direction of said upstream path.
The engine control device of claim 4 wherein
said bypass air path has at least an upstream side path that connects to the air-intake side of said throttle bore, and a downstream side path that connects to the exhaust side of said throttle bore; with said bypass air path being continuous and turning at least three times from said upstream side path to said downstream side path.
An engine control device comprising:
a throttle body;

a valve that opens or closes an air-intake path that is formed in said throttle body;

a throttle shaft that is mounted in said valve;

a rotation mechanism that rotates said throttle shaft;

a Throttle Position Sensor (TPS) that detects the position of the valve that opens or closes said air-intake path;

an air-intake pressure sensor that detects the pressure inside said air-intake path;

an air-intake temperature sensor that detects the temperature of the air-intake path; and

an ISC that controls the amount of air during idling; wherein

said TPS, said air-intake pressure sensor, said air-intake temperature sensor and ISC are located on the opposite side of said air-intake path from said drive mechanism.
The engine control device of claim 12 wherein said drive mechanism is an actuator that is rotated by the driving force from a drive source.
The engine control device of claim 12 wherein said drive mechanism is driven by a lever that is operated by a wire that is linked to an axle.
An engine control device comprising:
a throttle body having an air-intake path;

a sensor unit case that is formed in a process separate from said throttle body, and that houses a sensor unit comprising at least one sensor from among a TPS (Throttle Position Sensor) that detects the position of a valve that opens and closes said air-intake path, an air-intake pressure sensor that detects the pressure inside said air-intake path, and an air-intake temperature sensor that detects the temperature of said air-intake path; and

installation means for attaching said sensor unit case to said throttle body; wherein

said sensor unit case has an aggregate input terminal cover that houses an aggregate input terminal; and

the input section of said aggregate input terminal cover is located on the upstream side of said throttle body.
A two-wheeled vehicle that comprises the engine control device of anyone of the claims 1 to 15.