JPS588257A - Accelerator of carburretor - Google Patents

Abstract

PURPOSE:To make it possible to automatically adjust the rate of fuel discharge according to the change of temperature by making one spring among one or a plural number of coil shaped springs that directly or indirectly acts on a reciplcating member of an accelerating pump from a shape storing alloy. CONSTITUTION:A pump arm 1 makes contact with a piston rod 4 coupled to the piston 3 of an accelerating pump 2, and pushes down the piston 3 to cause fuel within a pump chamber 5 to be discharged when the opening of a throttle valve (drawing omitted) increases. Moreover, the pump chamber 5 is provided with an inlet 6 and an outlet 7 for fuel, and encloses in itself a return spring 8. And this spring 8 is made from a shape storing alloy such that it stretches according to the reduction of temperature to make a pump stroke large. Hereby, it is possible to increase the amount of fuel discharge at a low temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a carburetor accelerator device that automatically changes the amount of acceleration fuel in response to temperature changes to provide stable acceleration performance.

In accelerators that supply extra fuel to the wick, which temporarily increases the amount of intake air during engine acceleration, the amount of fuel discharged per operation of the accelerator pump decreases at high temperatures and increases at cold temperatures. There are some measures designed to provide stable acceleration performance. Conventionally, as a means for adjusting the discharge rate of a 770-speed pump, a reciprocating member consisting of a piston or a diaphragm of an accelerator pump and these? Some systems allow you to adjust the pump stroke and discharge amount by changing the connection position with the positive link mechanism, but this is troublesome and easy to forget as you have to change the connection position manually. However, in reality, it is hardly ever adopted. In addition, the link mechanism is provided with an extendable part whose length changes according to deterioration. Throttle or bypass on acceleration fuel passage? There are some models that allow automatic adjustment, such as adjusting according to the fuel ttf @ degree jetted from the acceleration nozzle into the intake passage, but the 1wl construction is complicated and special machining and parts installation are required. be.

The present invention has one or more coiled springs that act directly or indirectly on the reciprocating member of the accelerator pump, and is made of a shape memory alloy, so that special processing or addition of special parts is not required. Instead, the amount of fuel discharged is automatically adjusted by alteration.

A material having a shape memory effect, that is, a shape memory alloy, is known as a material whose shape changes reversibly with changes in temperature due to thermoelastic martensitic transformation.
-Ti, Cu-Al-Ni*Cu-Zn-kl
-N + a Fe Ni * N 1-kl *
Nb-Tie Cu-Zn-8ne Cu-Zn
A j e Cu -Z n + Cu-8n *
Fa−P t + Fe −B e g Fe −Mn
e I n-T e * Au -Cd * AJ'
Alloys such as -Zn are known as materials having a shape memory effect. These alloys reverse transformation end temperature A
If heat treatment is performed at a temperature higher than f to memorize the original shape, will it deform when the temperature decreases and becomes lower than the martensitic transformation start temperature Ms? The deformation stops when it starts and reaches the martensitic deformation end temperature Mf. When the temperature rises and becomes higher than the reverse transformation start temperature As, the deformation starts again and returns to the original shape when the reverse transformation end temperature Af is reached (see FIG. 1).

Therefore, by processing and deforming a material that has a memorized deer shape into a desired shape at a temperature lower than Mf, the transition! The shape reversibly changes between the original shape and the deformed shape within a range of degrees. When made from coiled spring shape memory 1 gold.

When it is compressed at a temperature lower than the memorized original shape Mf, it is deformed so that the coil length becomes shorter.

This spring expands as the temperature rises and contracts as the temperature falls. Conversely, when the spring is stretched and deformed so that the coil length becomes longer, the spring contracts as the temperature rises and expands as the temperature falls. Moreover, the force generated during expansion is strong and can apply a large load.

FIG. 2 shows the minimum transition temperature TL and maximum 7n of a coiled spring made of a shape memory alloy, and the temperatures Tl, T2. This is a characteristic curve diagram illustrating the relationship between the amount of deformation and the load at T3.

In the high temperature region, the amount of deformation is very small (Figure a).
It can be seen that the spring deforms to a practically effective amount only in a limited low temperature range. Shape memory effect by opposing this spring if necessary? When a bias spring made of non-metallic material is subjected to a load, the spring becomes #SK.
The amount of deformation is b, which is the minimum T of the dislocation temperature.
A practically effective deformation is carried out over the entire temperature range from t to maximum TH.

Changing the initial load or spring characteristics of the bias spring results in a deformation along a line parallel to line S.

Furthermore, as is clear from FIG. 1, the temperature at which the same amount of deformation is reached is different between when the temperature is raised and when the temperature is lowered. For the bias spring, the difference and decrease due to this hysteresis - K of fru is also useful, but it is possible to select and use a material with negligible hysteresis from among materials that have a shape memory effect, and in this case, the bias spring is not necessary.

In the case of a barge, the bias spring always applies a load to the expansion and contraction of the spring due to temperature changes, and moves in a controlled manner. The bias spring may be omitted so that it can move effectively.

The accelerator device for a carburetor according to the present invention includes, firstly, a damper spring that acts directly or indirectly on a reciprocating member of an accelerator pump, such as a damper spring that moves in a direction to reduce the volume of a pump chamber; A return spring that acts in the direction of increasing the volume of ? Those that act directly or indirectly, and thirdly, those that are used in combination with damper springs and return springs.

It is divided into three types. In the first and second types of accelerators, the damper spring, the return spring, is made of shape memory alloy. Alternatively, a control spring made of a shape memory alloy may be used to act as a bias spring, such as a damper spring or return spring made of a normal material that does not have a shape memory effect. In a third type of accelerator, either the damper spring or the return spring is made of a shape memory alloy. In this case as well, a bias spring made of a normal material can be additionally used, or a control spring made of a shape memory alloy can be used to act as a damper spring or a bias spring made of a normal material. be.

As stated at the beginning, the purpose of the present invention is to adjust the amount of acceleration fuel depending on the temperature, especially the engine temperature.
For this purpose, the stroke of the accelerator pump is controlled according to the temperature ft by utilizing the phase dislocation phenomenon caused by the thermoelastic martensitic transformation of a material having a shape memory effect, and the spring made of the shape memory alloy is less than or equal to Mf. For use between temperatures above and above Af.

It may also be used in a suitable temperature range between Mf and Af. Furthermore, depending on the installation location and the direction of action, springs made of shape memory alloys can be selected and used, such as those that have been processed and deformed from their original shape so that, for example, the coil length contracts or expands when the temperature cools. Needless to say.

As described above, according to the present invention, since one spring is made of a shape memory alloy, the fuel discharge amount of the η0-speed pump does not have to be manually controlled, and it does not require special 7JD machining or complicated parts construction. It can automatically adjust according to the temperature and provide stable acceleration performance without adding anything.

In addition, coiled springs made from shape memory alloys are bimetallic and change shape when heated.

The advantage is that the length changes due to temperature changes is larger than thermowax (product name), and its operation is highly reliable. Moreover, by simply replacing a conventional spring, the discharge amount can be controlled accurately.

Next, the drawings showing the embodiments of the present invention will be described.

In each example, the original shape was processed at a temperature higher than Af. Either a memorized coiled spring ff that is stretched at a temperature lower than Mf and subjected to Leloe deformation (2), or compressed at a temperature lower than Mf and subjected to processing deformation (7) is used.

[Embodiment 1] (Fig. 3) A pump arm 1, which is linked to a throttle valve (not shown) by a link mechanism, comes into contact with a piston rod 4 connected to a piston 3 of an acceleration pump 2, and when the opening of the throttle valve increases, the piston Push down 3 to pump fuel in pump chamber 5? Exhale. The pump chamber 5 has a fuel inlet 6 and a fuel outlet 7, and has a built-in return spring 8, so that the piston 3 has a volume of the pump chamber 5. In the direction of increasing the paddy grains. Enlarge.

[Embodiment 2] (Fig. 4) An auxiliary rod 9 is inserted between the pump arm l and the piston rod 4, and the piston rod 4 and the auxiliary rod 9 are connected to each other so as to be movable in the axial direction, and the piston 3 and A damper spring IO is provided between the auxiliary rod 9 and the auxiliary rod 9. This damper spring 10
Y is used, and as the temperature decreases, it contracts, increasing the pump stroke.

[Embodiment 3] (Fig. 5) An auxiliary rod 11 is inserted between the pump arm l and the piston rod 4, and the piston rod 4 and the auxiliary rod 11 are connected to each other so as to be movable in the axial direction, and there is a gap between them. damper spring 1
2 is provided.

In addition, a return spring 13 acts on the piston 3. The damper spring 12 is made of a normal material, the return 12 is made of Y, and the return spring 13 is made of a normal material.

[Embodiment 4] (Fig. 6) The pump arm 14 is the diaphragm 16 of the acceleration pump 15
&c makes contact with the piston rod 17 which is connected in series, and pushes the diaphragm 16 when the opening of the throttle ax increases, thereby discharging fuel from the pump chamber 18. The pump chamber 18 has a fuel inlet 19 and an outlet 2
0f@I, and a return spring 21 is built-in. Also,
A damper spring 22 acts on the pump arm 14. The damper spring 22 is made of a conventional material and the return spring 21 is either X or Y.

[Embodiment 5] (FIG. 7) A diaphragm 25 partitions a negative chamber 23 into which engine suction negative pressure is introduced and a pump chamber 24.

When the suction negative pressure decreases when the opening of the throttle valve increases, the diaphragm 25 moves toward the pump chamber 24 and discharges fuel.

Y is used as the damper spring 26 built in the negative pressure chamber 23.

[Implementation row 6] (Figure 8) In the same negative pressure type accelerator pump as in Fig. 7.

A bias spring 27 is built into the pump chamber 24. The bias spring 27 is made of a normal material and the damper spring 26 is made of Y, or the bias spring 27 is made of X and the damper spring 26 is made of a normal material.

[Brief explanation of drawings]

What are the characteristics of shape memory alloys in Figures 1 and 2? 3, 4, 5, 6, 7, and 8 are vertical cross-sectional views showing different embodiments of the present invention. 2.15...Acceleration pump, 3...φ...Piston, 5゜18.24...Pump chamber, Li2
．． 21...Return spring. 10.12, 22.26... Damper spring, 27
...Bias spring. f゛Agent Mutsumi Nozawa Aki Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] ll) An accelerator device for a carburetor, characterized in that one of the one or more coiled springs acting directly or indirectly on the reciprocating member of the accelerator pump is made of a shape memory alloy. . (2) A return spring that acts in the direction of increasing the volume of the pump chamber of the η0-speed pump acts directly on the reciprocating member, and this return spring is made of a shape memory alloy and processed to have a long coil shape at low temperatures. (3) The return spring acting in the direction of increasing the volume of the pump chamber of the accelerator pump acts directly on the reciprocating member, and at the same time decreases the volume of the pump chamber. A damper spring that acts in the direction of reciprocation is indirectly applied to the reciprocating member, and this return spring is made of a shape memory alloy with low melting temperature and a long coil length.
The D-shaped deformation is performed, and the damper spring has the shape chart 1 effect? Device according to claim (1), made of a material that does not have. (4) A return spring that moves in the direction of increasing the volume of the pump chamber of the accelerator pump acts directly on the reciprocating member, and a damper spring that moves in the direction of decreasing the volume of the pump chamber acts indirectly on the reciprocating member, This damper spring is made of a shape memory alloy and is deformed at low temperatures so that the coil length is shortened, and the return spring has a shape memory effect. N
The device according to claim (x), being made of L-free material. (5) A damper spring that moves in the direction of reducing the volume of the pump chamber of the accelerator pump acts directly on the forward and backward members, and this damper spring is made of a shape memory alloy and is designed to shorten the coil length at low temperatures. The device according to claim (1), which is processed and transformed into. (6) A damper spring that acts in a direction to decrease the volume of the pump chamber of the acceleration pump and a bias spring that increases the volume and moves in a smaller direction are directly applied to the reciprocating member, and this damper spring is made of a shape memory alloy and The device according to claim 1, wherein the bias spring is made of a material that is processed and deformed to shorten the coil length at low temperatures, and that does not have a shape memory effect. (7) A damper spring that acts in a direction to decrease the volume of the pump chamber of the accelerator pump and a bias spring that moves in a direction to increase the volume are directly applied to the reciprocating member, and this bias spring is made of a shape memory alloy and The device according to claim 1, wherein the coil shape is processed and deformed to become longer at a low temperature, and the damper spring is made of a material that does not have a shape memory effect.