JP2009063370A - Device and method for detecting number of idle revolutions of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an idle revolution number detector for an engine capable of accurately detecting the number of idle revolutions of an engine, by a device which is low cost and easy to handle. <P>SOLUTION: In the idle revolution number detector 10 for the engine, a first vibrating element 12A having a natural frequency of vibration which is equal to the vibration frequency of the engine 20 rotating at a regular idle speed is fixed to a base part 11. With the base part 11 fixed to the engine 20, the idle speed detector 10 detects the idle speeds of the engine 20, by resonance of the first vibrating element 12A. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an engine idling speed detecting device and an idling speed detecting method, and in particular, to easily detect an idling speed of an engine by an inexpensive and easy-to-handle apparatus without using a measuring instrument such as a tachometer. The present invention relates to an idling rotation speed detection device and an idling rotation speed detection method for an engine.

  If the idling speed when the engine is warmed up is not set within an appropriate range, the engine startability may deteriorate or the engine life may be affected. For this reason, the air-fuel mixture concentration is adjusted by operating the rotation speed adjustment mechanism, and the adjustment is performed so as to obtain an appropriate idling rotation speed.

The idling speed of a vehicle equipped with a tachometer can be set to an accurate idling speed by adjusting the tachometer while checking the engine speed. Further, as a vehicle not equipped with a tachometer independently, there is known an engine idling speed display device that displays an idling speed on a vehicle speed display device when a predetermined stop condition is satisfied (for example, a patent) Reference 1). However, a relatively inexpensive vehicle is often not equipped with a tachometer, and the idling speed adjustment of a vehicle not equipped with such a tachometer can be performed by using a handy tachometer as a tool to check the number of revolutions. Is done. However, since the handy-type tachometer is expensive, it is not uncommon to adjust the idling speed according to the operator's feeling.
JP 9-318640 A

  By the way, in the engine idling rotational speed detection device described in Patent Document 1, when the vehicle speed, the neutral position of the gear, and the engine rotational speed are detected, and the stop state of the vehicle is confirmed thereby, the vehicle speed display device is performed according to the display switching operation. The idling speed is displayed on the screen. For this reason, an apparatus for detecting the engine speed of the vehicle is necessary for the vehicle, and there is a strong demand for detecting the engine idling speed of the engine at a low cost and there is room for improvement.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an idling engine speed detecting device and an idling engine that can accurately detect the idling engine speed with an inexpensive and easy-to-handle device. An object of the present invention is to provide a rotational speed detection method.

  In order to achieve the above object, an invention according to claim 1 is an engine idling speed detection device, wherein a base portion fixed to the engine, one end fixed to the base portion, and the engine rotates at an idle speed. A vibration element having the same natural frequency as that of the engine at the time, and detecting the idling engine speed by resonance of the vibration element.

  In addition to the configuration of claim 1, the invention according to claim 2 has one end fixed to the base and the same natural frequency as the engine frequency when the engine rotates at a speed higher than the engine idle speed. Another vibration element having a length different from that of the vibration element is further provided.

  According to a third aspect of the present invention, in addition to the configuration of the first aspect, the vibration element includes a plurality of vibration elements having different natural frequencies corresponding respectively to the idling speeds of the plurality of engines. Features.

  In the invention according to claim 4, in addition to the structure of claim 1, the vibration element has a fixed position relative to the base, and the natural frequency can be adjusted by adjusting the length of the vibration element protruding from the base. It can be changed.

  The invention according to claim 5 is an engine idling speed detection method, wherein a vibration element having the same natural frequency as the engine frequency when the engine rotates at an idle speed is fixed to the engine; And a step of detecting the idling speed of the engine by resonating the vibration element when the engine rotates.

  In addition to the configuration of claim 5, the invention according to claim 6 is different in length from the vibration element having the same natural frequency as the engine frequency when the engine rotates at a speed higher than the idle speed of the engine. A step of fixing the other vibration element to the engine, and the detecting step is performed after the engine has been rotated to a rotational speed higher than the idle rotational speed by the resonance of the other vibration element. To do.

  According to the first aspect of the present invention, an engine idling speed detecting device includes a base portion fixed to the engine and a vibration element having one end fixed to the base portion. Since the vibration element has the same natural frequency as that of the engine rotating at the idling speed, the idling speed of the engine can be detected by resonance of the vibration element. Therefore, by visually confirming the resonance state of the vibration element, it is possible to easily detect the idling speed and adjust the idling speed with high accuracy.

  According to the invention of claim 2, the engine idling speed detecting device has one end fixed to the base and has the same natural frequency as the engine frequency when the engine rotates at a speed higher than the engine idling speed. Since the vibration element further includes another vibration element having a length different from that of the vibration element, after the engine speed is increased to the rotation speed at which the other vibration element resonates, the engine rotation speed is gradually increased to the rotation speed at which the vibration element resonates. By reducing it to the idling rotational speed, it is possible to detect the idling rotational speed in the same state as when using a normal engine, and to adjust the idling rotational speed with high accuracy.

  According to the invention of claim 3, since the vibration element includes a plurality of vibration elements having different natural frequencies corresponding to the idling rotational speeds of the plurality of engines, the resonance of each vibration element It is possible to detect the idling speed of a plurality of engines.

  According to the fourth aspect of the present invention, the natural frequency can be changed to an arbitrary frequency by making it possible to change the fixed position of the vibration element with respect to the base and adjusting the length of the vibration element protruding from the base. As a result, the engine speeds of a plurality of engines having different numbers of cylinders, displacements, idling speeds, and the like can be easily and accurately detected by the idling speed detection device of one engine.

  According to a fifth aspect of the present invention, there is provided a method for detecting an idling speed of an engine, the step of fixing a vibration element having the same natural frequency as the engine frequency when the engine rotates at an idle speed to the engine. The step of detecting the engine idle speed by the resonance of the vibration element during engine rotation includes the step of visually detecting the idling speed by visually checking the resonance state of the vibration element. The idling speed can be adjusted with high accuracy.

  According to the invention of claim 6, another vibration element having the same natural frequency as that of the engine when rotating at a speed higher than the engine idling speed and having a different length from the vibration element is fixed to the engine. And the detection step is performed after the engine has been rotated to a rotational speed higher than the idle rotational speed due to the resonance of the other vibration elements, so that the idling is performed in the same state as when using the normal engine. The rotational speed can be detected, and the idling rotational speed can be adjusted with high accuracy.

  Hereinafter, an idling engine speed detection device and an idling engine speed detection method according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a plan view of an engine idling speed detecting device according to an embodiment of the present invention, and FIG. 2 is a schematic plan view showing a state in which the engine idling speed detecting device shown in FIG. 1 is fixed to the engine. 3 shows the vibration state of the engine idling speed detecting device when adjusting the idling speed, (a) shows the engine idling speed detecting device detecting a higher speed than the normal idling speed, and (b). FIG. 5 is a plan view showing a state in which the engine idling speed detection device detects a normal idling speed.

  As shown in FIG. 1, the engine idling rotation speed detection device 10 of the present invention includes a base 11, a first vibration element (vibration element) 12A, and a second vibration element (other vibration element) 12B. . The base 11 is a plate-like member whose outer shape is formed in a substantially trapezoidal shape with metal, and a bolt hole 13 for inserting a bolt is formed in the center. The first and second vibrating elements 12A and 12B are, for example, piano wires having a diameter d = 0.5 mm, one end is fixed to the end surface 11a of the base 11 by welding or the like, and cantilevered substantially parallel to each other. It is extended to.

  The first and second vibration elements 12A and 12B have the same material, cross-sectional shape, etc., have natural frequencies determined by their lengths (L1, L2), and vibrations close to the natural frequency from the outside. When is added, it resonates and vibrates greatly. The length L1 of the first vibration element 12A is set to 122 mm, which is the same as the frequency of the engine 20 when the engine 20 is rotating near the normal idling speed (for example, within a range of 1400 rpm ± 100 rpm). The natural frequency is set. The natural frequency of the second vibration element 12B is set to the same natural frequency as the frequency of the engine 20 when rotating at a higher speed than the idling speed of the engine 20, and the length L2 is set to the first frequency. The length is shorter than that of the vibration element 12A.

  As shown in FIG. 2, such an idling rotation speed detection device 10 fixes the base 11 to the crankcase cover 22 or the like with a bolt 21 inserted through the bolt hole 13 when detecting the idling rotation speed of the engine 20 of the vehicle. Used. It should be noted that the mounting position of the idling rotational speed detection device 10 is preferably in the vicinity of the crankshaft, which is the main source of engine vibration, but may be anywhere where the vibration of the engine 20 is transmitted. It is not limited to 22.

  Next, the procedure for adjusting the idling speed of the engine 20 will be described. When adjusting the idling speed of the engine 20, first, as shown in FIG. 2, the idling speed detecting device 10 is fixed to the engine 20 with a bolt 21. Thereafter, the engine 20 is started, and the engine 20 after the warm-up operation is finished is set to an idling state. Then, a rotation speed adjustment mechanism (specifically, an idling adjustment screw) (not shown) is operated to increase the idling rotation speed. When the rotational speed of the engine 20 becomes higher than the normal idling rotational speed, the second vibration element 12B having a short length resonates with the vibration of the engine 20 and swings greatly (see FIG. 3A).

  Next, the rotational speed adjustment mechanism is operated to gradually reduce the rotational speed of the engine 20, the resonance of the vibration element 12B stops, and the long first vibration element 12A eventually resonates with the vibration of the engine 20. It will be in the state which shakes greatly (refer FIG.3 (b)). In a state where the first vibration element 12A swings to the maximum, the operation of the rotation speed adjustment mechanism is stopped, and the adjustment of the idling rotation speed is ended. Since the natural frequency of the first vibration element 12A is the same as the frequency of the engine 20 when rotating at the normal idling speed, the engine 20 has a normal idling speed (for example, 1400 rpm). ) It is detected that it is rotating in the vicinity.

  In the adjustment of the idling engine speed, once it was set to a higher engine speed than the normal idling engine speed, the engine speed was gradually decreased to set the normal engine idling engine speed. This is because the idling rotational speed is adjusted in a state approximate to the usage state of the above, and the idling rotational speed is accurately set.

  As described above, according to the engine idling rotation speed detection device 10 of the present embodiment, the engine 20 can be easily checked by visually confirming the vibration state of the first vibration element 12A without using an expensive measurement device. Can be confirmed to rotate at the normal idling speed, and thereby the idling speed can be adjusted quantitatively without depending on the operator's feeling. Further, since the idling rotation speed detection device 10 can be supplied at a low cost, a small-scale repair shop or the like who is difficult to introduce an expensive tachometer can also be used without a sense of resistance. Furthermore, if the idling rotation speed detection device 10 is installed in a vehicle as a vehicle-mounted tool, operation at the user level is possible.

  It should be noted that the frequency of the engine 20 is substantially the same at the same rotational speed if the number of cylinders is the same regardless of the magnitude of the engine displacement. Therefore, it is necessary to set the natural frequencies of the vibration elements 12A and 12B in accordance with the vibration frequencies of the respective engines.

  Here, the idling rotation speed detection device for an engine according to the present invention can be appropriately changed or improved as described below. The following various modifications are only partially different from the engine idling speed detection device 10 of the above-described embodiment already described with reference to FIGS. 1 to 3, and thus the same parts are denoted by the same or corresponding reference numerals. The description will be omitted or simplified.

  As shown in FIG. 4A, in the engine idling speed detection device 10A of the engine according to the first modification, a part 30 of the surface of the vibration elements 12A and 12B is colored with a conspicuous color such as red. As a result, when the vibration elements 12A and 12B resonate, as shown in FIG. 4B, the colored portion 30 spreads in a fan shape and is easily visually recognized, and the adjustment work is facilitated even in a dark place.

  As shown in FIG. 5A, in the engine idling revolution number detection device 10 </ b> B of the second modified example, the vibration elements 12 </ b> A and 12 </ b> B are fixed to the base 11 at a right angle. According to such an idling rotation speed detection device 10B, as shown in FIG. 5B, in the idling rotation speed detection device 10 of FIG. 1, the vibration elements 12A and 12B (indicated by broken lines in the figure) are frame covers 23. Even if the engine has a shape that is difficult to fix by interference with other components such as the above, it can be easily attached.

  As shown in FIG. 6 (a), in the engine idling speed detection device 10C of the engine of the third modification, the base 11 has a U-shaped groove 31 instead of a bolt hole. According to such an idling rotation speed detection device 10C, as shown in FIG. 6 (b), when attaching the idling rotation speed detection device 10C to the engine 20, it is not necessary to remove the bolt 21 from the engine 20; It can be easily attached, and the idling rotational speed adjustment work is further facilitated.

  As shown in FIG. 7, in the engine idling speed detection device 10 </ b> D of the fourth modified example, each vibration element 12 </ b> A, 12 </ b> B is formed by a flat element instead of a piano wire, A scale 32 is provided. Therefore, the idling rotation speed detection device 10D can be used as a scale, and the functions of the idling rotation speed detection device 10D are diversified to improve convenience.

  As shown in FIGS. 8 (a), (b), and (c), the engine idling speed detection devices 10E, 10F, and 10G of the fifth modified example are not provided with a base portion and are configured by only the vibration element 12A. Yes. In the detection device 10E shown in FIG. 8A, the vibration element 12A is configured by cutting a piano wire with a predetermined length, and one end thereof is sandwiched between the head of the bolt 21 and the engine 20 and fixed. Is done. In the detection device 10F shown in FIG. 8B, one end of the vibration element 12A to which the vibration element 12A is fixed is formed in a ring shape, and the bolt 21 is inserted into the ring-shaped hole and fixed to the engine 20. Further, in the detection device 10G shown in FIG. 8C, one end of the vibration element 12A to which the vibration element 12A is fixed is formed in a substantially U shape, and the U portion is hooked on the bolt 21 to the engine 20. Fixed. These idling rotation speed detection devices 10E, 10F, and 10G of the fifth modification can be manufactured at a lower cost than the idling rotation speed detection device 10 of the first embodiment.

As shown in FIG. 9, in the engine idling speed detection devices 10 </ b> H and 10 </ b> I according to the sixth modification, one or three vibration elements 12 </ b> A are fixed to the base 11. The idling rotation speed detection device 10H including one vibration element 12A is set to a natural frequency corresponding to the vibration frequency of a specific (one model) engine, and is used to adjust the idling rotation speed of the specific engine. Used. The engine idling speed detection device 10I including three vibration elements 12A can detect three kinds of vibration frequencies, and the idling speed of engines of a plurality of types (for example, single cylinder, four cylinders, and six cylinders). Adjustments can be made.
The number of vibration elements 12 is not limited to one or three, and an arbitrary number may be provided to correspond to the number of engines. Further, similarly to the idling rotational speed detection device of FIG. 1, other vibration elements 12B that resonate at a rotational speed higher than the normal idle rotational speed may be additionally disposed corresponding to a plurality of types of engines.

  As shown in FIG. 10, in the engine idling rotation speed detection device 10 </ b> J according to the seventh modification, the fixed position of the vibration element 12 </ b> A with respect to the base 11 can be changed. That is, as shown in FIGS. 10A and 10B, the base 11 is provided with a mounting hole (not shown) through which the vibration element 12 can be inserted together with the bolt hole 13. The vibration element 12 is inserted into the mounting hole and the protruding length L from the base portion 11 is adjusted to a predetermined length, and then firmly fixed to the base portion 11 by a fixing screw 33 penetrating the mounting hole. As described above, by adjusting the length L of the vibration element 12 protruding from the base portion 11, the natural frequency of the idling rotation speed detection device 10J can be set to an arbitrary frequency. Therefore, it is possible to adjust the idling rotational speeds of a plurality of types of engines 20 having different vibration frequencies with a single idling rotational speed detection device 10J.

  Further, as shown in FIG. 10C, the attachment position mark 34 is attached to the corresponding position of the vibration element 12A together with the engine type, the vehicle model name, the number of cylinders, etc., and the attachment position mark 34 is attached to the end surface of the base 11. If the length L of the vibration element 12A protruding from the base portion 11 is set to a length corresponding to each of the vibration elements 12A by being fixed in accordance with 11c, the convenience is further improved.

  The mounting structure of the vibration element 12A to the base 11 is not limited to the mounting hole and the fixing screw 33 described above, as long as the protruding length from the base 11 can be adjusted and the base 11 can be firmly fixed. Any thing is acceptable. Further, in addition to the above-described mounting holes, by forming other mounting holes parallel to the bolt holes 13, that is, perpendicular to the mounting holes, at positions where the fixing screws 33 penetrate, various shapes around the engine are formed. Can also be handled.

In addition, this invention is not limited to the said embodiment, A deformation | transformation, improvement, etc. are possible suitably. Moreover, the said embodiment and each modification are applicable in combination in the range which can be implemented.
In addition to the above-described piano wire, the vibration element of the present invention may be formed of a rod, plate, or coil having a predetermined natural frequency by a material having a certain rigidity such as metal or resin. it can.

It is a top view of the idling rotation speed detection apparatus of the engine of one embodiment concerning the present invention. FIG. 2 is a schematic plan view of an engine to which the engine idling rotation speed detection device shown in FIG. 1 is fixed. The vibration state of the engine idling speed detecting device at the time of adjusting the idling speed is shown. (A) is a state in which the engine idling speed detecting device detects a rotational speed higher than the normal idling speed. It is a figure which shows the state which the idling rotation speed detection apparatus of the engine detected the regular idling rotation speed. (A) is a top view of the idling rotation speed detection apparatus of the engine of a 1st modification, (b) is a figure which shows the state which the vibration element of (a) is vibrating. (A) is a perspective view of the idling revolution number detecting device of the engine of the 2nd modification, and (b) is a figure showing the state where the idling revolution number detecting device of (a) was attached to the engine. (A) is a top view of the idling rotation speed detection apparatus of the engine of a 3rd modification, (b) is the attachment figure. It is a perspective view of the idling rotation speed detection apparatus of the engine of the 4th modification. It is a figure which shows the state by which the idling rotation speed detection apparatus of the various engines of a 5th modification is attached to an engine. It is a top view of the idling rotation speed detection apparatus of the various engines of a 6th modification. (A) And (b) is a top view which shows the idling rotation speed detection apparatus of the engine of a 7th modification, and the change procedure of a natural frequency, (c) is the principal part enlarged view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Engine idling rotation speed detection apparatus 11 Base 12A 1st vibration element (vibration element)
12B Second vibration element (other vibration element)
20 engine

Claims (6)

A base fixed to the engine;
A vibration element having one end fixed to the base and having the same natural frequency as the frequency of the engine when the engine rotates at an idle speed;
An idling engine speed detecting device for an engine, wherein the engine idling engine speed is detected by resonance of the vibration element.   Another vibration element having one end fixed to the base and having the same natural frequency as the engine frequency when rotating at a higher rotational speed than the idle rotational speed of the engine, and having a different length from the vibration element; The engine idling speed detecting device according to claim 1, further comprising:   2. The engine idling speed detection according to claim 1, wherein the vibration element includes a plurality of vibration elements having different natural frequencies corresponding respectively to a plurality of engine idling speeds. apparatus. The vibration element is capable of changing a fixed position with respect to the base,
The engine idling rotation speed detection device according to claim 1, wherein the natural frequency can be changed by adjusting a length of the vibration element protruding from the base. Fixing a vibration element having the same natural frequency as the engine frequency when the engine rotates at an idle speed to the engine;
A step of detecting the idling speed of the engine by causing the vibration element to resonate during rotation of the engine;
An idling rotational speed detection method for an engine characterized by comprising: Fixing the vibration element having the same natural frequency as the engine frequency when rotating at a higher rotational speed than the idle speed of the engine to the engine, the vibration element having a different length from the vibration element;
Further comprising
6. The engine idling speed according to claim 5, wherein the detection step is performed after the engine is rotated to a speed higher than the idle speed by the resonance of the other vibration element. Detection method.

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