JPH0255875A - Governor advance device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industry> Second Field of Application The present invention relates to a governor advance angle "A vl", more specifically, a governor advance angle device incorporated in an automotive power distribution device to adjust the ignition timing of an engine. In particular, the present invention relates to a governor advance device suitable for engines where the angular acceleration of the engine is small.

<Prior art> In an engine power distribution device, as the rotational speed of the engine increases, the rotation angle of the crankshaft that rotates within a certain combustion time also increases, so the ignition timing of the engine needs to be advanced by that amount. There is a governor advance device used for this purpose.

FIG. 11 is a diagram showing the structure of a governor advance device conventionally used in a power distributor for an automobile engine. 1st
In FIG. 1, 1 is a drive shaft, 2 is a base plate fixed to the drive shaft 1, and a weight support shaft 3 and a spring rod 4 are fixed to the base plate 2, respectively. 5 is a weight, and at one end of the weight 5.

A pin 7 is installed as a drive pin and a spring hook, respectively. 8 is a timing lever integrated with the rotor shirt 1-9, and the timing lever 8 is provided with a cam groove 10 at a symmetrical position with the rotor shaft 9 as the center. Note that the rotor shaft 9 is rotatably attached to the drive shaft 1. In the figure.

Reference numeral 11 indicates a tension spring, which is an example of an elastic member.

The conventional governor advance device is configured as described above, and when the drive shaft 1 rotates and the entire device rotates, the weight 5 is caused to fly outward about the weight support shaft 3. A moment is received by the centrifugal force of the tension spring 11, and a moment 1 is generated by the elastic force of the tension spring 11.
- Leap forward to a position that is balanced with -.

In the process of this weight 5 flying out, the drive pin 6 implanted in the weight 5 is moved by the force t1 groove 1.
0, the timing lever 8 and the rotor shirt 1-9 integrally formed with the timing lever 8 are advanced relative to the drive shaft 1 with respect to the timing lever 8. in this way,
The governor advance device advances the relative advance angle between the drive shaft 1 and the rotor shirt 1-9 based on the balance between the centrifugal force determined by the rotational speed (angular velocity) of the rotor shaft 1 and the elastic force characteristics of the tension spring 11. It is something that creates. The curve indicated by a in FIG. 11 represents an example of the advance angle characteristic determined as described above.

However, the advance characteristics of the conventional governor advance device are determined only by the magnitude of the centrifugal force generated in the above-mentioned ways 1 to 5, in other words, the magnitude of the rotational speed of the drive shaft 1. However, the influence of the angular acceleration of the drive shaft 1 was not much considered. Therefore, in engines where large changes in angular acceleration occur in synchronization with combustion, extremely unstable advance angle characteristics may appear due to the inertial force generated in the weight 5 and timing lever 8 due to this angular acceleration. was there. That is, the inertial force Fw generated in the weight 5 acts on the center of gravity 12 of the weight 5, and as shown in FIG. 12, when the angular acceleration of the drive shaft 1 is negative, that is, when decelerating, the weight 5 is caused to fly further outward from the equilibrium position. On the other hand, when the angular acceleration of the drive shaft 1 is positive, that is, when it accelerates, a moment -F is generated that tries to return the weight 5 inward from the equilibrium position.
w-e occurs. Further, as shown in FIG. 12, the timing lever 8 (the moment of inertia around the drive shaft 1 is It) has a negative angular acceleration (-α) of the drive shaft 1.
In other words, during deceleration, a moment of It・α is generated, and this moment tries to cause the weight 5 to fly further outward from the equilibrium position through the contact point between the cam groove 10 and the drive pin 6, and conversely causes the weight 5 to fly outward from the equilibrium position. The angular acceleration of 1 is positive (assumed to be α), that is, when accelerating, a moment of 1 e·α is generated, and this moment tries to return the weight 5 inward from the equilibrium position.6 Generally, ignition of an engine is caused by its compression. Since the stroke is performed when the angular acceleration of the drive shaft 1 is negative, as mentioned above, the way 1-5 jumps further outward from its original equilibrium position, as shown by the curve b in Figure 13. This caused phenomena such as a jump in the advance angle, resulting in adverse engine symptoms such as knocking. Furthermore, as can be seen from FIG. 13, such a phenomenon in which the advance angle jumps up has a particularly bad effect when the rotational speed (angular velocity) of the drive shaft 1 is low, that is, when the advance angle is small.

As a measure to prevent the advance angle of the conventional governor advance device 11 from jumping up, there is a device described in, for example, Japanese Utility Model Application No. 61-41865.

<Problems to be Solved by the Invention> However, with the above-mentioned prior art, it is necessary to provide a new member called a stabilizing shaft to the configuration of the governor advance device, and the inertia force that tries to make the weight fly A moment is generated as before, and this moment is offset by a moment in the opposite direction generated by the stable shaft, so a large force in the opposite direction acts on the drive pin installed in the weight, Not enough consideration has been given to problems such as accelerating wear and deformation of the drive pin or the cam groove of the timing lever that contacts the drive pin, or the elongated hole provided in the stabilizing shaft.

SUMMARY OF THE INVENTION An object of the present invention is to provide a governor advance device that solves these problems and provides stable advance characteristics regardless of changes in the angular acceleration of the drive shaft.

Means for Solving the Problems To achieve the above object, the present invention provides a weight that flies outward due to centrifugal force generated by rotation of a drive shaft, an elastic member that provides elastic force to return the weight to the inside, A governor including a drive pin for advance provided on the weight, a timing lever engaged with the drive pin, and a rotor shaft that is advanced relative to the drive shaft via the timing lever. In the advance angle device, the center of gravity of the weight is set so that the inertia force generated in the weight due to the negative angular acceleration of the drive shaft becomes a moment in the direction of returning the weight inward, and the timing lever is provided with a center of gravity position of the weight. The cam groove is shaped so that the opening position of the way 1- does not change due to the inertia force generated on the timing lever due to the angular acceleration of the drive shaft. This allows stable advance angle characteristics to be obtained.

<Effect> The inertial force that creates a weight due to the negative angular acceleration of the drive shaft is a moment that moves the weight back inward!・Because of the roar, it is possible to prevent way 1- from flying further away from the equilibrium position, and the I! The jump position of the weight does not change depending on the inertial force generated on the timing lever due to the angular acceleration of the iK drive shaft, so there is no harmful phenomenon such as a jump in the advance angle due to a change in the angular acceleration of the drive shaft. Stable advance angle characteristics can be obtained.

<Example> An embodiment of the present invention will be described below based on the drawings.

FIG. 1 is a plan view showing the entire rod structure of a governor advance device according to the present invention, and FIG. 2 is a sectional view taken along the line AA in FIG. In the figure, the names of the members indicated by numerals 1 to 12 are exactly the same as those of the conventional governor advance device shown in FIG.

However, in the governor advance device of this embodiment, the position of the center of gravity 12 of the weight 5 is determined as described below. That is, in FIG. 3, the tangent extending from the center of gravity 12 of the arc passing through the center of gravity 12 centered on the yA drive axis toward the weight support shaft 3 is the line segment connecting the center of gravity 12 and the weight support shaft 3. The position of the center of gravity 12, in other words, the shape of the weight 5 and the position of the weight support shaft 3 are determined so that it is located between the rotation centers of the drive shaft 1. When the position of the center of gravity 12 is determined in this way, the moment FW-e created around the weight support shaft 3 by the inertia force Fw generated on the weight 5 due to the negative angular acceleration of the drive shaft 1 causes the weight 5 to move inward. trying to get it back.

On the other hand, the shape of the cam groove 10 provided in the timing lever 8 is determined as described below.

That is, in FIGS. 4, 5, 6, and 7, a
The angle θW between the common normal at the point of contact between the driving pin 6 and the cam groove 10 and the movement direction of the weight 5 is large; The angle θt formed with the direction of movement is determined to be small.

Frictional force between the opening pin 6 and the cam groove 1o does not act.
In other words, when the friction coefficient μ between the drive pin 6 and the cam ill l O is O (the case where the weight is driven is shown in Fig. 4,
(Figure 5 shows the case where the timing lever is driven).

The force l? exchanged between the weight 5 and the timing lever 8? is equal to the normal force N moving in the direction of the common normal at the point of contact between the opening pin 6 and the cam groove 10. At this time, out of the normal force N, the magnitude of the force effectively used by the timing lever 8 to move the ways 1 to 5 is N-cos
θw. Similarly, out of the normal force N, way 1
The amount of force effectively used by F5 to move the timing lever 8 is N-c.

s　Ot.

Next, the case where the frictional force acts between the drive pin 6 and the cam groove 10 will be explained (FIG. 6 shows the case of driving the weight, and FIG. 7 shows the case of driving the timing lever). The force F exchanged between the weight 5 and the timing lever 8 is the result of the normal force N acting in the direction of the common normal at the contact point between the quick-acting pin 6 and the cam groove 10 and the force between the drive pin 6 and the cam groove 1o. It is the resultant force of the frictional force μN between the two, and its magnitude is F=N
(1+μ”)'/2.

The angle between the resultant force F and the direction of movement of the weight 5 is φ
If the angle between W, the resultant force F and the direction of movement of the timing lever 8 is φt, φW=θW+muan-'μ, Oj=
: θt+tan−”μ, and φw>θw.

There is a relationship of φ and Ot. Therefore, out of the resultant force F, the magnitude of the force F-cosφW that is effectively used by the timing lever 8 to move the way l-5 is F-cosφ
w N-cos θw. Similarly, out of the resultant force F, the amount of force F-cosφL that is effectively used by the weight 5 to move the timing lever 8 is F-cos
φt<N-cosOt.

In other words, as the magnitude of F°CO8φw, F-cosφL and the friction coefficient μ increase, it becomes smaller, and finally, φ
When W and φ reach 90', the value becomes 0.

Let us summarize the considerations regarding the shape of the cam groove 10 mentioned above.

The function that the governor advance device should originally have, that is, the advance characteristic of the governor advance device, is determined only by the magnitude of the centrifugal force generated in the weight 5, in other words, the magnitude of the rotational speed of the drive shaft 1. Considering that the opening pin 6 must be able to easily move the timing lever 8 by 19 degrees due to the centrifugal force generated in the way 1-5, and the inertial force generated in the timing lever 8 must cause the opening pin 6 to move the timing lever 8 by 19 degrees. In other words, the weight 5 must not be easily driven.The shape of the cam groove 10 that satisfies these conditions is such that the angle aosφL, which is effective for the opening pin 6 to drive the timing lever 8, is large. 1 resultant force F to maintain
and the direction of movement of the timing lever 8, the angle φL=θ
t+tan-'μ is as small as possible, that is, 0L is as small as possible, and conversely, in order to keep the force F-cosφW that is effective for the timing lever 8 to drive the drive pin 6 small, the resultant force F and the direction of movement of the weight 5 should be Angle φW=
θw+tan−′μ is as large as possible, that is, θW is as large as possible. Furthermore, as can be seen from FIG. 13, the jump in the advance angle is particularly noticeable where the rotational speed (angular velocity) of the drive shaft 1 is small, that is, where the advance angle is small. In the shape of No. 10, the angle few between the common normal at the contact point of the opening pin 6 and the cam groove 10 and the movement direction of the weight 5 is particularly large.

All of the above considerations regarding the shape of the cam groove 10 were qualitative. Here, more quantitatively, the cam groove 10
I want to understand the shape of.

As mentioned above, the shape of the cam groove 10 is such that the force F・CO5φt effective for the opening pin 6 to open the timing lever 8
In order to keep the angle φ between the resultant force F and the movement direction of the timing lever 8 large, the angle φ = Ot + tan - "μ is as small as possible, that is, 01 is as small as possible, and conversely, in order for the timing lever 8 to drive the opening pin 6, effective force for ■
?・In order to keep cosφW small, the angle φW=θw+jan−”μ between the resultant force F and the direction of motion of the weight 5 is set as large as possible, that is, OW is set as large as possible.Reexamining this condition more strictly, Cam groove 1
When μwax is the maximum design-1 possible coefficient of friction between 0 and the drive pin 6, the necessary condition for the drive pin 6 to be able to move the timing lever 8 by 1li14 is QO5φ1> 0, that is, φ and 90°. From this relationship, when calculating the possible range of the angle o between the common normal at the contact point of the drive pin 6 and the cam groove 10 and the movement direction of the timing lever 8 when the maximum friction coefficient is μa+ax, we get φt=ot+t a n-'μn
+ax<90' or 3t<90' -t: a n
-"ptsax. Conversely, the necessary condition for the timing lever 8 to never move the drive pin 6, that is, the weight 5, is cosφwho, that is, φ>9
From this relationship, the maximum friction coefficient is μ+max
When calculating the possible range of the angle θW between the common normal at the point of contact between the drive pin 6 and the cam groove 10 and the movement direction of the weight 5, φw=θw+tan−'μax>
90°, that is, θw>90°−tan−′μm8X. The maximum friction coefficient μ+aax described above. The possible ranges of θw and θw are summarized in a graph and shown in FIG.

FIG. 9 and 1O- are diagrams showing θt and OW at each advance angle for the cam groove 10 of this embodiment, respectively. In Figure 9, the size of OL is Habo-30
'(θt<30'', which is very small, and in Figure 1O, the size of OW is 30°<θw<90
' and it's getting bigger. Furthermore, in FIG. 10, in a small range of advance angle where jumps in advance are likely to occur, θw has a particularly large value of nearly 90''.

The shapes of the cam grooves shown in FIGS. 1, 9, and 10 are merely examples of the present invention, and various advance angle characteristics can be obtained by using the concept disclosed in the present invention. In the governor advance angle device, safe advance angle characteristics can be obtained regardless of changes in the angular acceleration of the drive shaft.

FIG. 14 is an overall elliptical diagram of an automatic engine arrangement AM equipped with the governor advance device of the present invention. In Figure 12,
A joint 14 of a negative pressure response device (not shown) attached to the power distribution housing 13 is connected to a movable base 16 that is rotatably fitted loosely into a fixed base 15 fixed to the housing 13.
is connected to. A magnet 17 and a stator core 18 are mounted on the movable base 16, and an ignition timing control table Y120 including a detection coil 19 is mounted on the fixed base J5. On the other hand, a reluctor 21 is integrated into the rotor shirt ]-9 which is loosely fitted onto the drive shaft 1 driven by the engine. Therefore, when the gap between the stator core 18 and the reluctor 21 changes due to rotation, the magnet 17, the stator core 18. Reluctor 21. Rotor shaft9. The amount of magnetic flux with the movable base 16 as a magnetic path changes, and a voltage is generated in the detection coil 19. The ignition timing device 2o operates with this (it voltage), and the ignition timing is determined.

This signal voltage is applied to the aforementioned negative pressure response device (not shown),
A weight 5 attached to a base plate 2 integrated with the im motion axis 1. Tension spring 11. It is well known that the timing of occurrence changes and the ignition timing is determined by the governor advance device of the present invention, which is comprised of the rotor shaft 9, the timing lever 8, and the like.

According to the governor advance device of the present invention in a power distributor having such a configuration, a change in rotational acceleration of the engine, that is,
Since stable advance angle characteristics can be obtained regardless of changes in the angular acceleration of the drive shaft 1, the ignition timing can be stably determined and good ignition of the air-fuel mixture in the engine can be achieved.

<Effects of the Invention> As described above, according to the present invention, the inertial force generated in the weight due to the negative angular acceleration of the drive shaft becomes a moment in the direction of returning way 1- to the inside, and the Depending on the inertial force generated on the timing lever due to angular acceleration,
Since the jump position of the weight does not change, stable advance angle characteristics can be obtained without causing harmful phenomena such as jumps in the advance angle due to changes in the angular acceleration of the drive shaft6.

[Brief explanation of the drawing]

1 is a plan view showing the overall configuration of a governor advance device according to an embodiment of the present invention; FIG. 2 is a sectional view taken along line A-A in FIG. 1; FIGS. Figures 6 and 7 are diagrams for explaining the forces acting on the governor advance device, and Figure 8 is a diagram for explaining the forces acting on the governor advance device.
FIG. 3 is a diagram showing the relationship between the maximum friction coefficient μ1laX and the possible ranges of OL and θw. FIGS. 9 and 10 are diagrams showing OL and θw at each advance angle for the force t1 groove of this embodiment, and FIG. 11 is a diagram showing the structure of a conventional governor advance device. FIG. 12 is a diagram for explaining the force acting on the conventional governor advance device, FIG. 13 is a diagram showing an example of advance characteristics, and FIG. 14 is a diagram showing the governor advance device of the present invention. automatic 1
FIG. 2 is an overall configuration diagram of a power distributor for an f engine. Explanation of symbols 1... Drive shaft, 3... Weight support shaft, 5...
・Weight, 6...Late movement pin, 8...Timing lever 9・°°・Rotor shaft, 10...Cam groove, 11...Tension spring

Claims (1)

[Scope of Claims] 1. A weight that flies outward due to centrifugal force generated by rotation of a drive shaft, an elastic member that provides elastic force to return the weight inward, and a drive pin for advance angle provided on the weight. , a governor advance device comprising a timing lever engaged with the drive pin, and a rotor shaft that is advanced relative to the drive shaft via the timing lever; Setting the center of gravity of the weight so that the inertial force generated in the weight due to angular acceleration becomes a moment that returns the weight inward;
A governor advance device characterized in that the cam groove provided in the timing lever has a shape that prevents the jump position of the weight from changing due to inertia generated in the timing lever due to the angular acceleration of the drive shaft. 2. The position of the center of gravity of the weight is determined by a tangent extending from the center of gravity on an arc passing through the center of gravity around the drive shaft toward the support shaft of the weight, and a line segment connecting the center of gravity and the support shaft of the weight with the drive shaft. The governor advance angle device according to claim 1, wherein the governor advance angle device is located between the rotation centers of the governor. 3. The cam groove provided in the timing lever has a large angle between the common normal at the point of contact with the drive pin and the movement direction of the weight, and the angle between the common normal at the point of contact with the drive pin and the direction of movement of the timing lever is large. The governor advance angle device according to claim 1, characterized in that the angle formed by the direction of movement is small. 4. The cam groove provided in the timing lever has a relationship between the common normal at the contact point of the drive pin and the cam groove and the movement direction of the timing lever, where μmax is the maximum coefficient of friction between the cam groove and the drive pin. The range of the angle θt formed by is θt<90°-tan^-^1μmax
A patent claim characterized in that the range of the angle θw formed by the common normal at the contact point of the drive pin and the cam groove and the direction of movement of the weight is θw>90°-tan^-^1μmax The governor advance device according to item 1. 5. The cam groove provided in the timing lever has a shape in which the angle between the common normal at the contact point of the drive pin and the cam groove and the movement direction of the weight becomes particularly large when the advance angle of the rotor shaft is small. The governor advance device according to claim 3 or 4, characterized in that: