JPH0230309B2 - 2EKISEISETSUCHAKUZAINOBISHOTEIRYOTOSHUTSUHOHO - Google Patents

Description

[Detailed Description of the Invention] [Summary] A method for dispensing a two-component adhesive using a one-component dispenser, in which as the two-component adhesive is mixed and curing progresses over time, air is By changing the pressure and discharge time, it is possible to keep the discharge amount constant.

[Industrial application field]

The present invention relates to a method for dispensing a minute amount of a two-component adhesive, which maintains a constant discharge amount of the two-component adhesive used for bonding work of magnetic heads, etc., regardless of changes in the viscosity of the two-component adhesive over time. It is something.

For example, when bonding the gimbal of a magnetic head and the core slider, a two-component adhesive is used to obtain a strong and quick bonding effect, and the adhesive is It is required to dispense only a small amount. Also, if the amount of adhesive is not constant,
Variations in adhesive strength occur.

Therefore, it is necessary to use a two-component adhesive to control the discharge amount from the dispenser to a constant, minute amount.

[Conventional technology]

The minimum discharge amount of a two-component adhesive dispenser is:
At present, the limit is about 0.03 cc, so it cannot be applied when an extremely small amount of discharge is required as described above. Therefore, a two-component adhesive is discharged using a one-component dispenser.

If a one-liquid dispenser is used, it is basically possible to dispense a very small amount as described above. Conventionally, in order to dispense a two-component adhesive using a one-component dispenser, an air source 3 is connected to the rear of a syringe 2 containing the two-component adhesive 1, as shown in FIG. A pressure regulating valve 4 is provided between the syringe 2 and the air source 3, and the discharge pressure due to air pressure and the opening time of the pressure regulating valve 4 are adjusted to the required discharge amount taking into account the viscosity of the two-component adhesive 1. By adjusting the value accordingly, a predetermined discharge amount 6 can be obtained from the needle 5.

[Problem that the invention seeks to solve]

This conventional method does not take measures against changes in the viscosity of the adhesive. When dispensing a one-component adhesive using a one-component dispenser, the viscosity of the one-component adhesive before dispensing hardly changes unless the temperature changes.

However, when a two-component adhesive is to be dispensed with a one-component dispenser, the two-component adhesive with the main component and curing agent mixed in advance is put into the syringe 2, so over time The two-component adhesive in the syringe 2 is cured and its viscosity increases. The amount of discharge from the dispenser changes depending on the viscosity of the object to be discharged, and the influence of the viscosity is particularly large when dispensing a minute amount as described above.

Therefore, the discharge amount of the two-component adhesive decreases over time, resulting in a decrease in adhesive strength, which is a drawback.

The present invention was created in view of these points, and has a simple configuration that uses a single-liquid dispenser to dispense two liquids.
The purpose of this invention is to provide a control method that enables the dispensing of liquid adhesive in minute quantities.

[Means for solving problems]

FIG. 1 shows a principle circuit diagram of the method for dispensing a minute amount of a two-component adhesive according to the present invention.

In FIG. 1, a plurality of (two shown in FIG. 1) pressure regulating valves 4 are interposed in parallel between the syringe 2 and the air source 3. The set pressure of each pressure regulating valve 4 is a different value. A plurality of electromagnetic valves 7 are provided in series with each pressure regulating valve 4. Each electromagnetic valve 7 has a plurality of timers 8 to set the valve opening time, that is, the discharge time.

In this way, by combining the air pressure and the ejection time that can be arbitrarily set, a plurality of ejection conditions are created, and the ejection is performed in response to the change in the viscosity of the two-component adhesive 1 in the syringe 2 over time. The conditions necessary to keep the amount constant at a predetermined amount are experimentally selected in advance.

[Effect]

As the two-component adhesive 1 in the syringe 2 hardens over time, it is slightly reduced by applying air pressure under discharge conditions selected according to an experimentally determined order from among multiple discharge conditions. It becomes possible to discharge a fixed amount of two-component adhesive.

〔Example〕

FIG. 2 shows an embodiment of the present invention, in which three pressure regulating valves 4 are provided in parallel, and the air pressure in each pressure regulating valve 4 is set to 2 kg, 3 kg, and 4 kg, respectively.

Three solenoid valves 7 are provided corresponding to each pressure regulating valve 4, and each solenoid valve 7 is operated by a timer 8.
Three types of discharge time can be taken: 0.1 seconds, 0.2 seconds, and 0.3 seconds.

The discharge time determined by the opening of the solenoid valve 7 is determined by changing the discharge time under circumstances such as the need to make the diameter of the needle 5 extremely thin in order to reduce the discharge amount to a very small amount. A plurality of values can be arbitrarily set within a range in which the amount can be effectively changed and within a time range determined by the takt time.

Nine types of discharge conditions are prepared by combining the three types of discharge pressures and the three types of discharge times. These discharge conditions are controlled chronologically by a sequencer based on experiments in advance, according to an order that can correspond to the hardening of the two-component adhesive 1 in the syringe 2 over time, and the compression according to each condition is Under the action of air, 2
Bonding work is performed by discharging the liquid adhesive 1. As an example of the order in which the above discharge conditions are selected, initially the air pressure is 2 kg and the discharge time is 0.1 seconds, then the discharge time is changed to 0.2 seconds, then 0.3 seconds, and when the two-component adhesive has further hardened, the air pressure is Switch to 3Kg and set the discharge time to 0.1 seconds, then change the discharge time to 3Kg.
Change the ejection time to 0.2 seconds, then 0.3 seconds, and when the curing progresses further, increase the ejection time to 0.1 seconds, 0.2 seconds, and 0.3 seconds under an air pressure of 4 kg.
Change it to seconds.

If the dispensing conditions are changed in this way, the adhesion work is performed by dispensing a small amount of two-component adhesive, so the
Within a certain period of time during the pot life of the liquid adhesive, it is possible to always discharge a minute amount. Therefore,
Accurate bonding work can be performed with uniform adhesive strength and without staining the objects to be bonded.

〔Effect of the invention〕

As described above, according to the present invention, with an extremely simple air circuit configuration, a one-component dispenser can be used to create two-component adhesives while adopting dispensing conditions that correspond to changes in the viscosity of two-component adhesives. It is possible to discharge a small amount of the agent, which is extremely useful in practice.

[Brief explanation of drawings]

FIG. 1 is a principle circuit diagram of a method for dispensing a small amount of two-component adhesive according to the present invention, FIG. 2 is a circuit diagram showing an embodiment of the present invention, and FIG. 3 is a circuit diagram of a conventional method. In Figures 1 and 2, 1 is a two-component adhesive;
2 is a syringe, 3 is an air source, 4 is a pressure regulating valve,
7 is a solenoid valve, and 8 is a timer.

Claims (1)

[Claims] 1. Put the two-component adhesive 1 into a one-component dispenser, and adjust the air pressure applied to the two-component adhesive 1 in response to changes in the viscosity of the second adhesive 1 over time. A method for dispensing a minute quantity of a two-component adhesive, characterized in that the dispensing amount is made constant by adjusting and changing the dispensing time from 8 to a plurality of values using a timer.